LIBRARY OF CONGRESS. 

T3 en 

Chap, Copyright N<». 

Shelf ^\A) I \ 

UNITED STATES OF AMERICA. 



MAR 5 1901 



ENGINEERING 

FOR STEAM ENGINEERS. 



WRITTEN FOR THE BENEFIT OF THOSE MEN IN 

CHARGE OF STEAM PLANTS WHO WISH TO 

IMPROVE THEIR KNOWLEDGE OF STEAM 

ENGINEERING IN ORDER TO ENABLE 
THEM TO PASS EXAMINATIONS WHERE A 
LICENSE IS REQUIRED, AND TO DO MORE SAT- 
ISFACTORY WORK WHEREVER A STEAM ENGINE IS 

FOUND. 

BY W. H. WAKEMAN. 

AUTHOR OF "MODERN EXAMINATIONS OF STEAM ENGINEERS," "PRACTICAL 

GUIDE FOR FIREMEN." AND NUMEROUS ARTICLES FOR THE 

MECHANICAL PRESS. 



FIRST EDITION, ONE THOUSAND gO?I,ES, 




• - 



1 - > 



NEW HAVEN, CONN., U. S. A. 

PUBLISHED BY THE AUTHOR* 
1901. 



THE LIBRARY OF 

CONGRESS. 
Two Copies Received 

MAR. 5 1901 

Copyright entry 

CLASS Q. **W. No. 

COPY B. 






COPYRIGHTED 

By W. H. WAKEMAN, 
1900. 

ALL RIGHTS RESERVED. 






\ 









5r 



h3 



PREFACEo 



The adoption of compound, triple and quadruple 
expansion engines, necessitating the use of high 
steam pressures for their economical operation, the 
rapid increase in the number of high speed, direct 
connected engines, and the many appliances now 
found in every first-class plant for the saving of fu- 
el, the rapid generation of steam, and for increas- 
ing the life of the machinery, have added much to 
the care and responsibility of the steam engineer, 
so that in order to be competent for this kind of 
work means much more at the present time than it 
did a few years ago. 

In order to keep abreast of the times it becomes 
necessary for those who are in charge of steam plants 
not only to get as much experience as possible them- 
selves, but also to profit by the experience of others, 
as in this way it is possible for us to steer clear of 
the pitfalls which have made failures of the lives of . 
others, and have rendered their efforts for advance- 
ment of no avail. 

The study of well written books, treating of sub- 
jects that interest the steam engineer 5 is one of the 
most advisable ways of gaining knowledge, and that 
this volume may be considered an addition to those 
works which have proved to be of interest and value 
is the sincere wish of 

THE AUTHOR. 

New Haven, Conn. 




ENGINE ROOM 
OF THE BOARDMAN MANUAL TRAINING HIGH SCHOOL, 
NEW HAVEN, CONN. 
The "Workshop" of the Author. 



DEDICATION 



To those owners of steam plants, Master Mechan- 
ics of factories, Chief Engineers in charge of steam 
machinery, and Mechanical Engineers engaged in 
designing and erecting plants, who have ever been 
ready and willing to offer substantial encourage- 
ment to me while employed in work that is for the 
purpose of shortening the distance between the of- 
fice and the engine room, improving the condition 
of the steam engineer, and affording greater secu- 
rity to those who live and work in the vicinity of 
steam boilers, this book is respectfully dedicated 
by 

The Author. 

New Haven, Conn. 








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ENGINEERING PRACTICE AND THEORY. 

CONTENTS. 

CHAPTER i. 
The steam engineer holds a responsible position. 
He must know more than just enough to start and 
stop his engine. What constitutes a ( 'practical 
engineer. ' ' The "theoretical engineer, ' ' and why- 
he is so called. A combination of the two is de- 
sirable. Different kinds of steam and why they 
are so called. How water circulates in a boiler. 
The unit of measurement. Pounds pressure and 
what the term means. Molecules of water Heat 
a form of motion. 

CHAPTER 2. 
Safe pressures for our boilers and how to calculate 
them. Strength of joints. Pitch of rivets and 
thickness of plates. Why braces are used. Pitch 
of braces. Hollow stay bolts and their uses. 
Water legs. Fusible plugs and where they should 
be located. Troublesome plugs and a heroic 
remedy. A comparison. 

CHAPTER 3. 

Safety valves and their location. Rules. Distance 
from fulcrum to weight. What is the fulcrum. 
Why this rule is given. Proving the rule. De- 
termining the weight to be put on the lever. Cal- 
culating the pressure at which a valve will lift. 



CONTENTS. 

Length of lever. Determining the proper area of 
safety valve. Lever and pop valves. Caring 
for safety valves. 

CHAPTER 4. 
Heating surface of boilers and how to calculate it. 
Water tube boilers. What is the horse power of 
a boiler. Heating surface necessary. Latent, 
sensible and total heat. Proving the latent heat 
theory. How to condudl a test. Equivalent 
weight of wood and coal. 

CHAPTER 5. 
Calculating the duty of a boiler. Conducting a cal- 
orimeter test, and determining the water in steam. 
Water evaporated per pound of coal, and per 
pound of combustible. Equivalent evaporation. 
A problem in proportion. Another rule to pro- 
duce the same result. Percentage of moisture 
in steam. Its effect on the process. Accounting 
for the heat absorbed. 

CHAPTER 6. 
Two standards. A comparison. Heat units re- 
quired to evaporate one pound of water. Either 
standard may be used. Actual horse power of 
boilers. Actual and assumed conditions. Forc- 
ing boilers. Changing firemen often. Refusing 
to carry overpressure. A live engineer better than 
a dead hero. Penalty for carrying excessive pres- 
sure. 



CONTENTS. 

CHAPTER 7. 

Beginning of the day's work. Warming the cylin- 
der. The air pump should be started. Opera- 
ting the valve gear by hand. Starting a com- 
pound condensing engine. Water in the cylinder. 
The steam is admitted slowly. Calculating the 
power of engines. Single and double acting en- 
gines. 

CHAPTER 8. 

The indicator a recording steam gage. The pres- 
sure and the time important factors. A defective 
diagram. The loop and what it shows. The 
crosshead and the indicator drum. The mean ef- 
fective pressure. Dividing the diagram. Any 
accurate rule or scale may be used 

CHAPTER 9. 
Too slow a process for this age. Planimeters and 
their use. Power of a double engine. The com- 
pound engine and how to calculate its power. All 
of the steam not used. Objedl in building com- 
pound engines. Expansion in a single cylinder. 
Two kinds of constants. Horse power constant 
of the low pressure cylinder of a compound en- 
gine. 

CHAPTER 10. 
Estimating the power of a compound engine by us- 
ing one cylinder. Proportion of the two pressures. 
Adding them together. An illustration. Volumes 



CONTEXTS. 

of the two cylinders. Ratio of expansion for each 
cylinder. Adding the clearance. Another rule 
for the combined ratio of expansion. Ratio di- 
rectly from the diagrams. 

CHAPTER ii. 
Receivers. Great variation in sizes. Ratio of cyl- 
inders. One to seven. Converting a simple into 
a compound engine. When it will pay. Tandem 
and cross compound engines. Advantages and 
disadvantages. The steeple compound engine. 
Engineers have a choice of styles. 

CHAPTER 12. 
Horse power of a triple expansion engine. Care 
must be exercised when taking diagrams. The 
load will change. One indicator may answer ev- 
ery purpose. Calculating the combined ratio of 
expansion from the diagram. Making the'calcu- 
lation without using the intermediate cylinder. 
Four cylinder triple expansion engines. 

CHAPTER 13. 
Quadruple expansion engines. Condensing and non- 
condensing. Total expansion rate. Several forms 
of condensers. Advantages and disadvantages. 
The hot well. Air and circulating pumps. Us- 
ing condensing water several times over. Cool- 
ing towers. Great economy of water. Intelli- 
gent supervision needed. 



CONTENTS. 

CHAPTER 14. 

Weight of water. Temperature at maximum dens- 
ity. A pint and a pound. Foot pounds. Duty 
of a pumping engine. 100 pounds of coal and 
1000 pounds of steam. Various heights of reser- 
voirs. Pressure and height of a column of water. 
Weight and fri<5tion. Indicating the water cyl- 
inder. Improvements in pumping engines. 

CHAPTER 15. 

When it is not necessary to weigh the coal. Time 
required to use iooo pounds of steam. Steam and 
water. Pounds of coal burned and pounds of wa- 
ter evaporated. The Corliss pumping engine. 
The George F. Blake engine. The Allis triple 
expansion pumping engine. The high duty at- 
tachment on the Worthington pumping engine. 
Philosophy of its operation. Result when the 
water main bursts. The engine at New Haven > 
Conn. 

CHAPTER 16. 
The pressure that a pump will work against. Boil- 
er feeders. Pressure required to run a pump. 
Diameter of water piston required. Diameter of 
steam piston. Four rules and their application. 
Piston, plunger and power pumps. Capacity of 
pumps. Size of pump required to raise a given 
quantity of water. Diameter of water pipe. Speed 



CONTEXTS. 

of water in pipes. Air-tight covering for suction 
pipes. 

CHAPTER 17. 
Lifting and nonlifting injectors. Double tube, sin- 
gle tube, fixed and automatic injectors. Peculiar- 
ities of the different kinds. Effect of varying 
steam pressure. Internal parts must bear a cer- 
tain relation to each other. Wear of tubes and 
accumulation of scale. Cleaning an injector. It 
must be properly connected. Cause of failure to 
force hot water. A high and a low lift. Taking 
water under pressure. Operating against a higher 
pressure than is carried on the boiler. Theory of 
the injector. Loss of heat. Calculating the ve- 
locity of steam. Discharge of steam through an 
orifice. Weight of steam and of water delivered 
to the boiler. Foot valves. 

CHAPTER 18. 

Object sought in covering a steam pipe. Amount 
of steam condensed in a pipe. Square feet of sur- 
face and degrees difference of temperature. 
Amount of coal wasted. Porous coverings. Sen- 
sible and latent heat. Heat lost. Equivalent in 
horse power. Saving effected by using pipe cov- 
ering. 

CHAPTER 19. 
Heating with exhaust steam. Removing cylinder 



CONTENTS. 

oil and grease. Live steam heating. Varying 
amounts needed. Reducing valves. Back pres- 
sure on the piston and pressure in the system. 
Loss of heat in doing work. Power used. Steam 
used per minute. Heat units disappear in doing 
work. The indirect system of heating with forced 
blast. 

CHAPTER 20. 
Reducing pressure by the engine and by the reduc- 
ing valve. Temperature of steam after passing 
the reducing valve. Explanation of the phenom- 
enon. Specific heat of steam. Condensation in 
the radiators. Open tanks. Return traps. The- 
ory of their operation. Receivers and pumps. 
Heating the cold water. Steam users should ap- 
preciate a good engineer. 



A NATURAL CONSEQUENCE. 
When people visit the engine and boiler rooms of 
a mill, factory or electric station, they form opin- 
ions of the ability and general qualifications of the 
engineer in charge, and these opinions are based on 
the general appearance of the rooms and the ma- 
chinery in them, therefore every engineer should 
care for his plant to the best of his ability, regard- 
less of the compensation received, for this is the best 
way to secure a better situation. 




When an engine revolves in the direction indicat- 
ed by the arrow, it runs "over." This is theprop- 
er way for an engine to run. 



i 



:3 




1 k ^ l^ 



When an engine revolves in the direction indicat- 
ed by the arrow, it runs "under." This plan should 
be avoided whenever it is possible to do so. 



CHAPTER i. 

DUTIES OF THE STEAM ENGINEER. 



When we consider the great variety of conditions 
under which the steam engineer of the present time 
is called upon to pursue his labors, the different 
kinds of machines that he is expected to understand, 
and the weight of responsibility that rests upon 
him, the necessity of a thorough knowledge of the 
principles which govern the action of all his ma- 
chines and appliances is at once recognized. 

It is not enough for him to know how to start and 
stop his engine day after day, but he must under- 
stand its construction, and also have a complete 
knowledge of his boilers and every adjundl of his 
plant, not only that he may properly care for this 
important machinery, but that it may be operated 
in the most economical way, and when repairs be- 
come necessary they may be made in the best and 
least expensive manner. 

To do all that is required along these lines calls 
foi a cool head, steady nerves, good judgment and 
that self-confidence which only comes through a 
knowledge of every detail of the work in hand. 



l6 ENGINEERING PRACTICE 

This constitutes what is very properly called a 
c 'practical engineer. n When a man thoroughly 
understands why it is that certain causes produce 
certain effects throughout the plant, it is proper to 
call him a "theoretical engineer," and a combina- 
tion of the two makes a very desirable man to have 
in charge of a steam plant. 

We frequently find ourselves unable to readily re- 
ply to questions, the answers to which we naturally 
think are familiar to us, but find it otherwise at 
times. 

Every engineer knows what steam is, but not all 
can define it when the matter is referred to them. 
Steam is an elastic fluid resulting from the combi- 
nation of heat with water. When steam is in con- 
tact with the- water from which it was generated, 
but without water held mechanically in suspension, 
its temperature corresponds to its pressure, and it 
is known as saturated or dry steam. 

If it holds water in suspension it is called wet 
steam, but if subjected to more heat after being sep- 
arated from the water that it was generated from, 
its temperature is then increased, without producing 
a corresponding increase of pressure, and it is then 
called superheated steam. In other words, super- 
heated steam has a higher temperature than its pres- 
sure calls for, and in this condition it is nearly a 
perfect gas, so that it is sometimes called gaseous 
steam. 



AND THEORY. 1 7 

When we build a fire under a horizontal boiler the 
water directly above the fire is heated first, and as 
a natural consequence rises to the highest point pos- 
sible. The space vacated by this water is at once 
filled by water rushing forward from the rear part 
of the boiler, and the space vacated by this water is 
in turn filled by the heated water that first arose to 
the surface. This process will be continued as long 
as heat is applied to the water. 

In order that we may make necessary calculations 
it is advisable for us to have some standard unit for 
the measurement of heat, and this is known as the 
British Thermal Unit, and is often designated by 
its initial letters B. T. U. 

It means the amount of heat required to raise the 
temperature of one pound of water at 39 Fah. one 
degree, or from 39 to 40 . It is assumed that the 
temperature of the water is 39 because at that 
point it has attained its maximum density. The 
Universal Heat Unit would be a more appropriate 
name. 

After a great many heat units have been added 
to the water in the boiler, steam is generated, and 
as more heat is applied the pressure increases, the 
amount being indicated by the pointer of the steam 
gage. Here another problem is presented, for we 
may be asked to explain what it means when the 
pointer indicates 50 pounds pressure. We should 



i8 ENGINEERING PRACTICE 

reply that it means 50 pounds to the square inch on 
the surface of the boiler, and the pounds are so 
much weight just as when tea and sugar are weighed. 
A column of water 1 inch square and 27.7 inches 
high at a temperature of 62 weighs one pound, and 
50 pounds would be 50 x 27.7 = 1,385 inches, or 
115 feet high. If we had suitable appliances for 
holding this in place, and allowing the steam pres- 
sure to act on the bottom of it, we could measure 
the pressure by observing the height, but this would 
be higher than some of the water gages on vertical 
boilers, and they are too high for convenience. 

If a steam gage was connected at the base of this 
column it would indicate 50 pounds, and if the size 
of the column was changed the pointer would still 
indicate 50 pounds as long as the height remained 
the same, for the simple reason that the height in- 
dicates the pressure per square inch. 

A molecule of water is the smallest particle of 
water that can exist, and when water is at 39 Fah. 
it is at its maximum density, because these mole- 
cules lie as closely together as possible. 

If heat is applied until 212 at sea level is reached 
they continue to separate, and if more heat is then 
applied they are forced much farther apart, and the 
water is turned into steam. The pressure is light 
at first, but as more water is evaporated in a closed 
vessel the pressure increases, the molecules are 



AND THEORY. I( j 

forced closer together, and the steam becomes more 
dense. Heat is a form of motion, hence the greater 
the temperature the more rapid will be the motion 
of the molecules. 




A TYPE OF BOILER THAT WILL NOT BECOME OBSO- 
LETE FOR MANY YEARS TO COME. 



20 ENGINEERING PRACTICE 



CHAPTER 2. 
SAFE WORKING PRESSURE. STAY BOLTS AND BRACES, 

FUSIBLE PLUGS. 



We do not wish to raise more pressure on our 
boiler than it will safely stand, hence must under- 
stand something of the rules that are given us for 
the purpose of determining the safe working pres- 
sure of any boiler. The following is a very good 
one : 

Multiply one-fifth of the tensile strength of the 
iron or steel by the strength of the joint and by the 
thickness of the plate. Divide by the radius, or 
one-half the diameter of the boiler. The quotient 
will be the safe working pressure. 

Suppose that the tensile strength is 50,000 
pounds, the joint has .70 of the strength of the solid 
plate which is .5 inch thick and the diameter is 72 
inches. Then (50,000 -r- 5) X .70 X .5 -f- (72 -*- 2) 
= 97 pounds safe working pressure. 

The strength of the riveted joint may be found 
as follows : 

From the pitch of the rivets subtract the diam- 



AND THEORY. 21 

eter of rivet, and divide the remainder by the pitch 
of the rivets. Multiply the quotient by 100 and the 
produdl will be the strength of the plate at the joint. 
Multiply the area of one rivet by the number of 
rows of rivets, and by the shearing strength of riv- 
ets, which may be taken at 38,000 pounds. Divide 
the product by the pitch of rivets multiplied by the 
thickness of plate, and by the tensile strength of 
plate. Multiply the quotient by 100 and the prod- 
uct will be the strength of the rivets. In each case 
the result will be the per cent of the strength of 
the solid plate, and the lowest must be used in the 
calculation. 

For illustration, suppose that the pitch is 2 
inches, the rivets .75 inch in diameter, the area of 
which is .44 square inch, and the plate is .5 inch 
thick. The joint has two rows of rivets. 

2 — .75 
Then X 100 = 63 per cent for the strength 

2 of the plate. 

.44X2X38,000 

X 100 = 67 per cent for strength 

2X.5X 50,000 of rivets. 

In this case we should call the strength of the 
joint 63 per cent of the solid plate, as the lowest 
must be taken. To compute the area of rivet, 
square its diameter and multiply by .7854 the same 
as for the area of any circle. 



22 ENGINEERING PRACTICE 

Braces are put into a boiler to strengthen the flat 
surfaces, as they are weak parts. They must be lo- 
cated near enough to each other to prevent the plate 
between them from springing. The following is 
one of the U. S. Government rules for determining 
the proper distance from center to center of braces 
or stay bolts : 

Multiply the area of cross section of brace or stay 
bolt by 6000. Divide by the steam pressure and 
extract the square root of the quotient. Applying 
this to the case of a head f inch thick, using braces 
i£ inch in diameter, where we wish to carry 100 
pounds pressure gives the following, the area of the 
brace being 1 square inch : 

1 X 6000 -5- 100 = 60 the square root of whicfr is 
7.75 therefore the braces should be 7.75 inches from 
center to center. The only real difference between 
a brace and a stay bolt is that the former is longer 
than the latter. 

Stay bolts are sometimes made hollow so that 
when corrosion has weakened them sufficiently to 
allow the water to enter the hollow part the appear- 
ance of it w r ill warn the engineer of the dangerous 
condition of them. When hollow stay bolts are put 
in above the grates of an internally fired boiler they 
admit air above the fire and promote combustion. 
As complete combustion prevents smoke they an- 
swer a double purpose. 



AND THEORY. 23 

The water leg of a boiler refers to that part of a 
locomotive, vertical or marine boiler in which an 
outer and an inner shell are parallel, or nearly so, 
making it necessary to conned! them with stay bolts. 
Some tubular boilers are made with water fronts 
extending down below the shells, forming water 
legs below the furnaces. 

A fusible plug is a hollow isesrplug, which should 
be filled with pure tin, and in the case of a tubular 
boiler it had ought to be located in the rear head 
about 3 inches above the upper row of tubes, so that 
if the water level falls until the plug is uncovered 
the filling of tin will be melted out, and the escap- 
ing steam will give sufficient notice of the condition 
of affairs. In other forms of boilers it is located in 
some convenient place just above the lowest water 
level that can be permitted, so that it will melt out 
before the boiler is burned for lack of water. 

The hollow part of the iron plug should be larger 
on the side that is exposed to the boiler pressure, so 
that there will be no danger of its being blown out 
before it melts. Care should be taken to keep the 
internal part of it free from scale and sediment, as 
otherwise it may not melt out as soon as the water 
level falls below it. 

I have heard of an engineer who was troubled 
with fusible plugs, as he found it necessary to renew 
them at short intervals. Desiring to make a per- 
manent job of it he drove in tapering iron plugs in- 



24 ENGINEERING PRACTICE 

stead of putting in the tin filling. He succeeded in 
preventing further failure of the plugs, but his ac- 
tion was on a level with that of the man who re- 
moves the low water alarms from his boilers, or fixes 
the whistles on them so that they cannot sound an 
alarm, even if there is great need of one. Or it 
might be compared to the work of the man who 
fastened a piece of timber between his safety valve 
lever and the floor timbers above it, in order to pre- 
vent the annoying noise caused by the steam blow- 
ing into the room. 



ADVICE BASED ON EXPERIENCE. 
If you are an engineer in charge of a steam plant, 
and have decided to leave your present situation, 
give your employer due notice that you are going 
to leave, and recommend a suitable man to take the 
place. Dishonorable acts on his part in the past 
does not excuse you from this duty, as your reputa- 
tion for honorable dealing is at stake. 



AND THEORY. 



25 



STEAM 




A VERTICAL TUBULAR BOILER WITH BRICK SETTING. 

This type of boiler has no water leg to corrode, 
or stay bolts to break. The tubes are so arranged 
that a large steam space is secured, and it supplies 
dry steam. 



26 ENGINEERING PRACTICE 



CHAPTER 3. 

SAFETY VALVE RULES. 



Every boiler should have a safety valve located 
on a separate outlet from the shell, and there 
should be no stop valve between it and the boiler. 
Where an engineer takes charge of a new plant he 
may wish to know whether the weights are properly 
adjusted on the safety valves or not, and to deter- 
mine this the following rule applies : 

Multiply the area of valve by the pressure to be 
carried, and by the distance from the valve to the 
fulcrum. Call this answer No. 1. Multiply weight 
of valve and stem by their distance from the ful- 
crum, and call this No. 2. Multiply one-half of 
length of lever by its weight, and call this No. 3. 
Add No. 2 and No. 3 together and subtracl the sum 
from No. 1. Divide the remainder by the weight 
of ball, and the quotient will be the distance from 
the fulcrum to the ball. 

The fulcrum in this case is the bolt which passes 
through the end of lever, fastening it to the bonnet 
of the safety valve. I give this rule for two reas- 



AND THEORY. 2J 

ons. First, because it was found in a standard book 
of reference supposed to be corredl, and second, be- 
cause I have proved it and found that it gives very 
good results. 

It is not such a hard matter to prove some of these 
rules as might be supposed, for in this case all that 
was required was to improve the chance when one 
of my boilers was cool and empty to make some 
measurements and prove some weights. Taking the 
ball from the lever and weighing it I found that it 
balanced the scales at 76 pounds. The valve and 
its stem weighed 4 pounds, and the lever which was 
34 inches long weighed 5.5 pounds. As the valve 
was 4 inches in diameter its area was 12.56 square 
inches, and the distance from stem to fulcrum is 2 
inches. The pressure to be carried is 65 pounds. 
Applying the foregoing rule we have 12.56 X 65 
X 2 = 1,632.8 for answer No. 1. 4X2=8 for an- 
swer No. 2 and (34 -f- 2) X 5.5 = 93.5 for answ r er 
No. 3. Then8 + 93.5 = 101.5 and 1,632.8 — 101.5 
= 1,531.3 Dividing this by 76 shows that the ball 
should be set at 20.15 inches from the fulcrum. 

Putting the valve together I placed the weight as 
near to this distance from the fulcrum as could be 
determined in the case of such a rough casting as 
we usually find a safety valve ball to be, got up 
steam and noted the effe<?t. When the steam gage 
pointer indicated 65 pounds the valve commenced 
to blow off steam. 



28 ENGINEERING PRACTICE 

In using the rule for determining the weight to be 
put on a safety valve lever the same process is em- 
ployed as above described, except that in the latter 
part of it we divide by the distance from the ful- 
crum to the ball, and the quotient is the w T eight of 
the ball to be put on the lever. In this case it is 
I o3 I -3 -*■ 20.15 = 76 pounds. 

The rule for determining the pressure at which a 
safety valve will open is as follows : 

Multiply weight of ball by its distance from the 
fulcrum, and call it answer No. 1. Multiply weight 
of valve and stem bv their distance from the ful- 
crum, and call it answer No. 2. Multiply one-half 
of the weight of lever by its length, and call it an- 
swer Xo. 3. Add these three answers together and 
divide the sum by the area of the valve, multiplied 
by its distance from the fulcrum, and the quotient 
will be the pressure in pounds. 

Applying this rule to the valve already men- 
tioned gives the following result: 76 X 20.15 = 
1,531.4 for No. 1. 4 X 2 = 8 for No. 2. (34 -£- 2) 

X 5-5 = 93-5 for No - 3- Then z>53 z -4 + 8 +93-5 
-7- (12.56 X 2) = 65 pounds pressure. 

When designing a lever for a safety valve of this 
boiler we take the maximum pressure that the boil- 
er can safely withstand, and proceed as directed in 
the first rule in this chapter. In this case as we do 
not know what the length of the lever is, we will 



AND THEORY. 29 

assume a length for it, and give it a trial. Taking 
the pressure at 100 pounds, and the extreme length 
of lever at 34 inches, we proceed as follows : 12.56 
X 100 X 2 = 2,512 for No. i. 4 X 2 — 8 for No. 2. 
(34-^-2) X 5-5 = 93-5 for No. 3. 8 + 93.5= IOI -5 
and 2,512 — 101.5 = 2,410.5. Dividing this by 76 
shows that the ball should be 31.7 inches from the 
fulcrum for this pressure. As the lever must pro- 
ject beyond this, 34 inches will be right for it. It 
will be noted that the addition of 2 or 3 inches af- 
fects the result but very little. 

It is a good plan to base the calculations for de- 
termining the necessary area for a safety valve on 
the grate surface, assuming a good natural draft. 
A lever valve should have one square inch area for 
each two square feet of surface. If a grate is 5 feet 
square, then 5X5-^-2 = 12.5 square inches. Re- 
ferring to a table of areas of circles we find that this 
corresponds to a 4 inch circle, therefore the valve 
should be 4 inches in diameter. 

If a pop valve is used, one square inch for each 
3 square feet will answer, because this kind of valve 
is more efficient than a lever valve, and 5X5-^-3 
= 8.3 square inches, which calls for a 3^ inch valve, 
or the next size larger, if this cannot be procured. 

Safety valves should be kept free from dust and 
dirt, they should be tried every day to demonstrate 
that they will lift at the required pressure, and when 
found leaking they should be ground in without de- 
lay. 



3° 



ENGINEERING PRACTICE 




This pop safety valve has no lever to be overload- 
ed, and its nickel seat prevents it from sticking, thus 
giving it a clear title to the name, "safety valve. n 
The short lever shown is for the purpose of testing 
the valve by hand. 



AN AXIOM. 
When an engineer is notified that after a certain 
date his services will no longer be required, he should 
run his engine to the specified time, and leave ev- 
erything in good order for his successor. 



' mww % 



AND THEORY. 3 1 



CHAPTER 4. 

HEATING SURFACE OF BOILERS. CONDUCTING TESTS. 



The heating surface of a steam boiler refers tc 
those portions of the shell and tubes which are ex- 
posed to the action of fire on one side, and covered 
with water on the other. If we take a horizontal 
tubular boiler 66 inches in diameter and 15 feet long, 
with 96 three inch tubes, we may calculate the heat- 
ing surface in it as follows, assuming that one-half 
of the shell is exposed to the fire : 

The circumference of a circle is found by multi- 
plying its diameter by 3.1416 and 66 X 3.1416 = 
207.34 inches, or 17.28 feet. Multiplying by the 
length we have 17.28 X 15 = 259 square feet, one- 
half of which is 129.5 square feet in the shell. 
There are 96 tubes each 15 feet long, making 1,440 
feet in length. It requires 1.373 ^ eet ^ n length 
of 3 inch tubing to make one square foot of heat- 
ing surface, therefore 1,440 -f- 1.373 = 1,049 
square feet of heating surface in the tubes. There 
is but a small amount in the heads, and they may 
be omitted, for it cannot be called very effective 
heating surface. Then 129.5 + I >°49 = 1,178.5 
square feet of heating surface in the boiler. 



32 ENGINEERING PRACTICE 

When calculating the heating* surface of other 
boilers, if the tubes are 3? inches in diameter, divide 
the total length by 1.17 and if they are 4 inches di- 
vide by 1.02 to obtain the square feet in them. 

In the case of water tube boilers ascertain the 
length of all the tubes in inches, multiply by the 
circumference in inches, divide by 144 and the quo- 
tient will be the number of square feet of heating 
surface. 

Or multiply the length of one tube in feet by the 
number of tubes in the boiler, and in the case of 4 
inch tubes, which are very commonly used, divide 
by -955 The quotient will be the number of square 
feet of heating surface. 

Where tubes of other sizes are in use their surface 
may be determined by the following table, taking 
the inside surface for fire tube, and the outside for 
water tube boilers : 

EXTERNAL DIAMETER. INSIDE SURFACE. OUTSIDE SURFACE. 



I 


4.46 


3.82 


1.25 


3-45 


3.06 


i-5 


2.86 


2-55 


i-75 


2-45 


2.18 


2 


2.ir 


1. 91 


2.25 


1.85 


i-7 


2-5 


1.67 


i-53 


3 


t-37 


1.27 


3-5 


1. 17 


1.09 


4 


1.02 


•95 



AND THEORY. 33 

The horse power of a boiler is its power to evap- 
orate a given amount of water per hour under stated 
conditions, which are explained in chapter 6. 

No inflexible rule for the amount of heating sur- 
face required per horse power can be given, but the 
following will be found convenient in making esti- 
mates where the amount of water evaporated is not 
known : 



Tubular boilers, 


15 square feet 


Locomotive " 


1 5 


» rr 


Vertical 


18 


rr rr 


Flue 


10 


rr // 


Cylinder 


8 


// // 


Water tube '' 


12 


n rr 



The latent heat of steam is the heat that is not 
indicated by the thermometer, and the sensible heat 
of steam is that which is indicated by the thermom- 
eter. When reference is made to the total heat of 
steam we mean the latent and sensible heat added 
together. 

Some people tell us that there is no such thing 
as latent heat, but as the following experiment has 
been tried it will be rather hard to explain it away. 
Two glass vessels were provided and made to connedt 
with each other by means of a tube connected into 
the top of each. One pound of water w r as put into 
one, and 5^ pounds into the other, the temperature 
of both being 32 Fah. Heat was applied to the 
lighter one until all of the water was evaporated and 



34 ENGINEERING PRACTICE 

passed over into the heavier one. Then it contained 
6? pounds of water at 212° Fah. 

To raise one pound of water from 32° to 212 re- 
quires 180 heat units, and to raise 5? pounds calls 
for 5^ X 180 = 990 heat units. These must have 
come from the one pound of water that was evapo- 
rated into steam, for they could not have come from 
anywhere else, therefore the claim that steam does 
possess latent heat is proved to be correct, although 
the tables give the number of heat units at 966 in- 
stead of 99c. 

The objects sought in conducting boiler tests are 
to determine the comparative efficiency of steam 
boilers, and the power that they are developing. 

When a test is to be conducted the water level 
may be at any convenient point, and the steam 
should be raised to a working pressure. All of the 
fire should then be withdrawn, and the weight of dry 
wood used to build a fresh fire carefully noted. When 
this is multiplied by .4 it gives the equivalent weight 
of coal, which must be added to the actual weight 
of coal used. 

The height of the water in the glass should be 
carefully noted, and the coal to be burned weighed 
as it is brought to the furnace for use. A sample of 
it should be weighed, then dried, weighed again 
and the moisture it contains calculated from this. 
The per cent of moisture so obtained must be sub- 
tracted from the total weight of coal as brought to 



AND THEORY. 35 

the boiler room, for if the sample contained, say 2 
per cent of moisture, then 2 per cent must be sub- 
tracted from the total weight of coal delivered. 

All of the water must be weighed, and the quality 
of the steam tested by means of a calorimeter, that 
we may know how much water it contains. This 
water- must be deducted from the total amount 
pumped into the boilers, for it is not evaporated, 
but inasmuch as its temperature has been greatly 
increased due credit should be given for the heat so 
used. 

At the conclusion of the test the fire should be run 
down as low as possible, and the remainder drawn 
out. The unburnt coal remaining must be deducted 
from the amount charged to the test, and all of the 
ashes weighed, so that when their weight is sub- 
tracted from the weight of coal charged we may 
know how much combustible was consumed. The 
water level should be brought to the same point that 
it was at the commencement of the test. We are 
now ready to make our calculations. 



ADVICE BASED ON OBSERVATION. 
If you own a steam plant and have decided to dis- 
charge your engineer, tell him so in a straightfor- 
ward manner, giving him reasons for your decision, 
and allow him a reasonable time in which to secure 
another situation. 



36 



ENGINEERING PRACTICE 




AND THEORY. 37 

IMPROVED VERTICAL BOILER. 
The vertical boiler illustrated on the opposite 
page has hollow stay bolts above the grate, does not 
require a brick furnace, and it supplies dry steam. 
The tubes are spaced so that it is possible to keep 
the crown sheet clean, and hand holes are properly 
located for this purpose. 




"LEST WE FORGET." 
When a steam user is notified that after a certain 
date his engineer will be found in the service of an- 
other party, he should allow the engineer to run his 
engine to the specified time, then give him a suit- 
able recommendation, in writing, and speak a few 
words of encouragement to show that past services 
are not forgotten. 



/ 4|v 



38 ENGINEERING PRACTICE 



CHAPTER 5. 

CALCULATING THE DUTY OF A BOILER. 



A calorimeter is an instrument or a device for de- 
termining the percentage of moisture in steam. 
There are several kinds of calorimeters, but the use 
of the most simple form will be explained here, as 
it is easily understood and the results obtained by it 
are correct for all practical purposes. 

Care must be taken to secure a sample of steam 
that correctly represents the quality that is generat- 
ed by the boiler, and in order to accomplish this a 
long thread should be cut on a small pipe, so that 
it may be screwed into the large pipe from which 
the sample is to be taken, until the end of it reaches 
the center of the large pipe. This is necessary be- 
cause there is always at least some water on the 
bottom of a horizontal pipe, and frequently drops of 
water will trickle down the sides of a vertical pipe. 

Having inserted the small pipe and provided a 
valve for regulating the flow of steam through it, a 
calorimeter test may be conducted in the following 
described way : Take a keg, or a tub that will hold 
about ten gallons, set it upon a pair of scales and 



AND THEORY. 39 

carefully note its weight. Fill it about three-quar- 
ters full of clean water, note the weight again, sub- 
tract the former from the latter and the remainder 
will be the weight of water, the temperature of 
which must be noted. Blow steam into it until the 
temperature is raised to about 125 Fah., stir it 
thoroughly and note its exact temperature. Weigh 
the heated water, subtract the weight of cold water 
from it and the remainder will be the weight of 
steam used, or condensed. 

From the temperature of the water as it now 
stands subtract the temperature of the cold water, 
multiply the remainder by the weight of cold water 
and divide the produ6l by the weight of condensed 
steam. To the quotient add the temperature of the 
heated water, and subtract the sum from the total 
heat of steam at the pressure carried on the boiler, 
reckoned from zero. If this total is taken from a 
table that gives it above 32 it will be necessary to 
add 32 to the number found. Divide the remainder 
by the latent heat of the same steam, and the quo- 
tient will be the percentage of moisture in the steam. 

In order to illustrate the operation of this rule I 
took a piece of f inch pipe, cut a long thread on it, 
and screwed it into a 3! inch pipe in the plant that 
I have charge of, until it would take steam from the 
center of the large pipe. Using a pair of scales that 
are graduated to tenths of a pound, I found that the 
tub it was convenient to use weighed 6.25 pounds. 



4-0 ENGINEERING PRACTICE 

Pouring in a quantity of cold water the whole 
weighed 35.68 pounds, so that the weight of cold 
water was 29.43 pounds, and its temperature was 
13 Centigrade, or 55. 4 Fahrenheit. Steam was 
blown into this cold water until its temperature was 
raised to 55° C. or 131 Fah. The temperature in- 
dicated by the Centigrade scale may be changed to 
the Fahrenheit by multiplying the former by 1.8 
and adding 32 to the product. 

The whole now weighed 38.4 pounds, showing 
that 2.72 pounds of steam were condensed. The 
pressure carried at this time was 70 pounds abso- 
lute, the total heat of which from zero is 1,205.8 
heat units, and the latent heat is 900.8 heat units. 
Carefully following the rule already given it was 
found that the steam contained .28 per cent or about 
-] of 1 per cent of moisture. Steam for use in this 
plant is supplied by two horizontal tubular boilers 
without domes. 

If we divide the number of pounds of water evap- 
orated by the pounds of coal shoveled into the fur- 
nace, minus the weight of moisture it contains, the 
quotient will be the pounds of water evaporated per 
pound of coal. 

When we take the weight of coal shoveled into 
the furnace, minus the moisture, and subtract from 
it the weight of coal, clinkers and ashes left in the 
furnace and ash pit, the remainder will be the weight 
of combustible used. 



AND THEORY. 41 

When we divide the total weight of water evap- 
orated by the weight of combustible used we have 
the pounds of water evaporated per pound of com- 
bustible. 

When we ascertain the weight of water that would 
have been evaporated if the feed was at 212 Fah. 
and the pressure at zero by the gage, and divide it 
by the weight of combustible used, we have the 
pounds of water evaporated from and at 212 per 
pound of combustible. 

The latter is used almost exclusively for compar- 
ing the efficiency of different boilers, and as they are 
seldom or never used under these conditions, an ex- 
planation of the process for reducing their actual 
performances to its equivalent from and at 21 2° is 
here given. 

Let A equal the total heat of steam under the as- 
sumed conditions, minus the temperature of the feed 
water. Let B equal the total weight of water evap- 
orated under the actual conditions. Let C equal 
the total heat of steam under the actual conditions. 
Let D equal the weight of water that would have 
been evaporated under the assumed conditions. 
Then A : B : : C : D. 

To solve a problem of this kind, multiply B by C, 
divide the produdl by A, and the quotient will be D. 
The total heat of steam is reckoned from zero in 
this case. 



42 ENGINEERING PRACTICE 

For illustration, take steam at o pounds pressure, 
or zero by the gage, which contains 1,178 heat 
units per pound above zero. The temperature of the 
feed water is 212 . Then 1,178 — 212 = 966 which 
is the value of A. The water actually evaporated 
was 20,000 pounds, which is the value of B. The 
pressure on the boiler at the time of test was 80 
pounds by the gage, or 95 pounds absolute, the total 
heat of which is 1,212. The feed water was sup- 
plied at 190 , and 1,212 — 190 = 1,022 which is 
the value of C. When we have solved the problem 
it stands as follows : 

966 : 20,000 : : 1,022 : 21,159. 
Therefore the evaporation of 20,000 pounds of water 
under the actual conditions is equal to evaporating 
21,159 pounds under the assumed conditions. 

Suppose that the weight of coal used during this 
test, taking it as it came from the coal yard, was 
2,052 pounds, audit contained 5 per cent of mois- 
ture. The actual weight of coal would then be 
2,052 — (2,052 X .05) = 1,950 pounds. The rule 
foi determining this is as follows : 

Weigh a sample of coal as delivered, then thor- 
oughly dry it and weigh it again. Subtract the 
latter weight from the former, divide the remainder 
by the weight of moist coal, multiply the quotient 
by 100, and the product will be the percentage of 
moisture. 



AND THEORY. 43 

In order to illustrate this rule I took a small box, 
weighed it, filled it with a sample of coal and 
weighed both together. They were then kept in a 
warm place until all of the moisture was evaporated, 
when they were weighed again, after which the coal 
was emptied out and the box weighed with the fol- 
lowing result : 

The box originally weighed 4.9 pounds and when 
filled with moist coal the weight was 18. 1 pounds, 
showing that the box contained 13.2 pounds of coal 
and moisture. When the whole was dry it weighed 
16.9 pounds and the empty box weighed 4.4 pounds, 
showing that the actual weight of coal was 12.5 
pounds. The moisture in the coal weighed 13.2 — 
12.5 = .7 pound, which is .7 -f- 13.2 X 100 = 5 per 
cent of moisture, or in other words the moisture 
amounts to .05 of the total weight. 2,052 X .05 = 
102 pounds, and 2,052 — 102 = 1,950 pounds of dry 
coal. This shows that the box lost .5 pound weight 
by the drying process. 

As 1,950 pounds of dry coal were used, then 21,159 
-f- 1,950 = 10.85 pounds of water evaporated from 
and at 212 per pound of dry coal. 

If the refuse weighed 187 pounds, then 1,950 — 
187 =1,763 pounds of combustible. 21,159 -1- 1,763 
= 12 pounds of water evaporated from and at 21 2° 
per pound of combustible. 

There is another way in which this may be com- 
puted, as follows : 20,000 pounds of water were 



44 ENGINEERING PRACTICE 

evaporated and 1,763 pounds of combustible were 
used, therefore 20,000 -f- 1,763 = 11.34 pounds of 
water evaporated per pound of combustible under 
actual conditions. If we call this the value of B our 
problem is as follows : 

966 : 11.34:: 1,022 : 12 
showing as before that 12 pounds of water would be 
evaporated under assumed conditions. 

In the foregoing calculation it is assumed that the 
calorimeter test showed the steam to be dry, or in 
other words all of the water pumped into the boiler 
was evaporated into steam, but frequently this is 
not the case as some of it passes off in the form of 
water. 

If the calorimeter showed that there was 5 per 
cent of moisture in the steam, then 20,000 X .05 = 
1000 pounds of water passed off without being evap- 
orated, so that 20,000 — 1000 = 19,000 were actu- 
ally converted into steam. 

This water entered the boiler at a temperature of 
1 90° and as it passed out with the steam at 95 
pounds absolute pressure its temperature was 324. 8° 
so that each pound of it had absorbed 324.8 — 190 
= 134.8 heat units, or 134,800 heat units for 1000 
pounds. 

The total heat of this steam is 1,212 and the tem- 
perature of the feed water is 190° therefore it re- 
quires 1,022 heat units more to evaporate each pound 
of it. As 134,800 heat units have been absorbed it 



AND THEORY. 45 

is equivalent to evaporating 134,800 -r- 1,022 = 132 
pounds of water, making a total of 19,132 pounds. 

This is corre6l for cases where the feed water is 
pumped through an exhaust steam heater, or through 
an economizer, as the heat thus put into the water 
would otherwise be a waste product. Where a live 
steam heater is used, or an injector puts water di- 
rectly into a boiler without a heater, the tempera- 
ture of the water must be taken before artificial heat 
is applied, or in other words when it is in its natu- 
ral state. 

Where an injector is used and the water is forced 
through an exhaust steam heater the temperature 
of the water must be taken both before and after it 
passes through the injector. Subtracting the for- 
mer from the latter gives the number of heat units 
that is put into each pound of it by live steam which 
is not a waste product. This difference must be 
subtracted from the temperature of the water as it 
leaves the heater, and the remainder is the amount 
to be subtracted from the total heat of the steam. 

Suppose that in the case previously mentioned 
where 19,000 pounds of water were evaporated, an 
injector was used to feed the boiler, the water enter- 
ing it at 50 Fah., and it was forced directly into 
the boiler. The total heat of the steam is 1,212 
and subtracting the temperature of the water shows 
that 1,162 heat units more are required to evapo- 
rate each pound. 134,800 -^ 1,162 = 116 pounds, 



46 ENGINEERING PRACTICE 

and adding this to the amount evaporated shows that 
it is equivalent to evaporating 19,116 pounds under 
these conditions. 

If the water had been forced through an exhaust 
steam heater, entering it at no Fah. and leaving 
it at 190 3 then no — 50 = 60 and 190 — 60 = 130 
heat units to be subtracted from the total heat. 
1,212 — 130 = 1,082 heat units to evaporate each 
pound. 134,800 -T- 1,082 == 124 pounds. There- 
fore under these conditions it would be the same as 
evaporating 19,124 pounds of water. 

These rules may be applied to any test by using 
the figures which correspond to the conditions under 
which the test is conducted, and by comparing the 
results secured in different cases the comparative 
efficiency of any number of boilers may be deter- 
mined. 

The process of determining the amount of water 
that would be evaporated from and at 212° when 
the amount evaporated under actual conditions is 
given is called "Finding the equivalent evapora- 
tion." 

If some other standard is adopted the reduction 
of actual results to this standard comes under the 
same general head, but in such a case the preferred 
standard must be clearlv stated. 



AND THEORY. 



47 




This water tube boiler has a horizontal steam 
drum and inclined water tubes. Steam may be 
raised in it quickly from cold water, and it gives 
good results in practice. 



A SUGGESTION. 
When you are in charge of a plant where the con- 
ditions are unsatisfactory, and the pay is small, 
then is the time to qualify for a better situation. 



f^t^ f*v* irir 

'«% r*r* rmrm 



48 ENGINEERING PRACTICE. 



CHAPTER 6. 

ACTUAL HORSE POWER OF BOILERS. 



There are two standards for calculating the actual 
horse power that a boiler is developing. 

The standard adopted by the American Society 
of Mechanical Engineers calls for the evaporation 
of 344 pounds of water per hour, from feed at 2i2 D 
Fah. into steam at o pounds pressure. 

The standard adopted at the Centennial Exposi- 
tion at Philadelphia, Pa., in 1S76, is the evapora- 
tion of 30 pounds of water per hour, from feed at 
100 D Fah. into steam at 70 pounds gage pressure. 
Let us compare them and note the difference. 

To evaporate one pound of water at 21 2° Fah. 
into steam at o pounds pressure requires 966 heat 
units, as explained in Chapter 5, and 34} pounds 
requires 34' x 966 = 33,327 heat units. 

The total heat of steam at 70 -f- 15 = 85 pounds 
absolute pressure is 1,210 and as the feed is sup- 
plied at ioo : we subtract that amount, and find 
that it requires 1,110 heat units to evaporate one 
pound of water under these conditions. To evapo- 



AND THEORY. 49 

rate 30 pounds requires 30 x 1,110=33,300 heat 
units, showing that there is practically no differ- 
ence between the two standards, so that the engi- 
neer may use either one at his discretion. The 
Centennial Standard will be used in these calcula- 
tions. 

The rule for finding the actual horse power that 
a boiler is developing is as follows : 

Divide the number of pounds of water evaporated 
into dry steam, by the number of hours covered by 
the test, and the quotient will be the amount evap- 
orated per hour. Reduce this to its equivalent 
evaporation from feed at ioo° into steam at 70 
pounds gage pressure, and divide the answer by 
30. The quotient will be the actual horse power 
developed by the boiler. 

Suppose that while running n hours we pumped 
30,306 pounds of water into the boiler, and on test- 
ing the steam according to the rule given in Chap- 
ter 5 we find 2 per cent of moisture present. 
30,306 x .02 =606 pounds of water in the steam. 
Then the amount actually evaporated would be 
30,306 — 606= 29, 700 pounds. Dividing this by 11 
shows that 2,700 pounds were evaporated per hour. 
The steam pressure was 95 pounds by the gage, 
and the feed water was supplied at 195 Fah. Ap- 
plying the formula given and explained in Chapter 



5<3 ENGINEERING PRACTICE. 

5, which is A : B : : C : D. we have 1,110 : 2,700 
:: 1,021 : 2,483 pounds, which is the amount that 
would have been evaporated from feed water at 
100 into steam at 70 pounds gage pressure. 

It must be noted, however, that during the test 
of 11 hours, 606 pounds of water were carried off 
in the steam, or 55 pounds per hour. This was 
raised from the temperature of the feed water, 
which was i95°tothetemperatureof the steam which 
was 334° therefore each pound of water took up 
334 — 195 = 139 heat units, and 55 pounds would 
take up 7,645 heat units. Under the assumed con- 
ditions it requires 1,110 heat units to evaporate one 
pound of water, therefore the heat taken up by this 
water is equal to the evaporation of 7,645 -f- 1,110 = 
7 pounds nearly, which must be added to the 
amount already found, and 2,483 + 7 = 2,490 
pounds evaporated per hour. As 30 pounds con- 
stitute a horse power 2,490 -f- 30 = 83 horse power 
actually developed. 

From the foregoing it will be seen that the horse 
power of a boiler is a clearly defined quantity, and 
may be calculated at pleasure, provided the neces- 
sary data are supplied. 

The practice of forcing boilers beyond their rated 
capacity is a pernicious one, and should be discoun- 
tenanced on every convenient occasion. It is true 
that where boilers are forced, the first cost of a 



AND THEORY. 51 

plant is less than if sufficient boiler power had been 
provided to allow the fires to be run at a moderate 
rate, but this advantage is more than overbalanced 
by the reduction of time that boilers may safely be 
used under such conditions, by large repair bills 
made necessary, and the hardships to men who 
operate the plant, causing frequent changes in the 
force, which, as a rule, does not operate to the 
advantage of the owners. All of these are but the 
natural consequences of operating a plant on this 
basis. 

It seems to be the opinion of some steam users 
that their engineers should carry whatever pressure 
is necessary to do the work required of the engine, 
and instances are known w r here men have been dis- 
charged for refusing to carry more pressure than 
they believed to be safe. 

When the safe working pressure of a boiler has 
been decided in an intelligent manner by a compe- 
tent engineer or inspector, it should never be 
exceeded. Where an engineer is called upon to 
decide between ruining his boiler and losing his sit- 
uation, it should not require very much time to set- 
tle the question,' for a live engineer is better than a 
dead hero every day in the week, and where a man 
loses his life without becoming a hero, he is more 
than unfortunate. 



52 ENGINEERING PRACTICE. 

The penalty for carrying excessive pressure on a 
boiler should be severe, and it should be applied to 
both owner and engineer alike, forever disqualify- 
ing them from owning or operating steam boilers. 
We deal sternly with a man who takes the life of 
one person, but what shall we do w r ith those who 
willfully cause the loss of many lives? 



v V^^ / 



/ /^^Tv \ 



/W®^ 



A MISTAKEN IDEA. 

People frequently think that an engineer in 
charge of a steam plant has but little to do, because 
there are times when he is not actively engaged 
in manual labor. This certainly is a wrong idea of 
the situation, because there are many days when the 
engineer must be at work long before the other 
men are required to be in the mill or factory, and 
he must also remain after they have gone home. 
When this is taken into consideration it will be 
plain that the engineer has a full day's work of 
manual labor to perform, and in addition to this he 
has the care of the plant continually on his mind. 



AND THEORY, 



53 




AN EFFICIENT SAFETY BOILER. 



54 ENGINEERING PRACTICE 



CHAPTER 7, 



STARTING THE ENGINE. HORSE POWER 
DEVELOPED. 

The first duty of an engineer, when coming into 
his plant in the morning, is to see that his boilers 
are in proper condition to furnish steam, and that 
the firemen are in their places, ready for the work 
to be done. The engine may next receive atten- 
tion, and he should note carefully whether there 
are any indications of the derangement of the valve 
gear or other parts. The oil cups should be in- 
spected and every part properly oiled, ready for 
duty. While this is being done, the drip valve on 
the main steam pipe should be left open, and all of 
the water in the pipe allowed to escape. If the 
design of the engine admits of it, he should open 
the steam and exhaust valves, and blow steam 
through the steam chest and cylinder, for the pur- 
pose of thoroughly warming these parts before an 
attempt is made to start the machinery. 

Where it is not convenient to open all of the 
valves together, one steam valve should be opened 



AND THEORY. 55 

and steam admitted to warm that end of the cylin- 
der, after which the other should be opened and 
the other end warmed. This refers to an ordinary 
non-condensing engine, but if there is a condenser 
the air pump should be started at the same time 
that steam is admitted, provided it can be run inde- 
pendently of the engine, in order that the v/ater 
of condensation may be disposed of. 

Having warmed the cylinder by blowing steam 
through it, the valve rod should be hooked on to 
the stud made for it, and enough steam admitted 
to start the engine slowly. It is the practice of 
some engineers to operate the valve gear by hand 
during several revolutions of the engine. It is 
claimed that this is done for the purpose of work- 
ing water out of the cylinder, but this is not rea- 
sonable, for if any one who is interested will follow 
out the operation they will discover that to throw 
the wrist plate of a Corliss engine, over in advance 
of the motion of the eccentric, closes the exhaust 
valve while the piston is advancing towards it, thus 
not only failing to assist the water to escape, but 
closing the only exit for it, before it would be 
closed were the valve gear in proper place for 
running. 

The process of starting a compound condensing 
engine is very similar to starting a simple condens- 
ing engine, as the air pump should be running 



56 ENGINEERING PRACTICE 

that the water of condensation may be removed, 
but care must be taken to see that both cylinders 
are well warmed before the wheel makes a revolu- 
tion. If the low pressure cylinder contains water 
at this time, the pressure on the high pressure piston 
and the momentum of the fly wheel may cause the 
low pressure piston to be driven against this water 
with sufficient force to result in making a wreck of 
some of the parts. With whatever kind of engine 
the engineer may have to deal, he should admit 
steam very gradually at first, allowing the fly wheel 
to revolve slowly until the whole machine is well 
warmed, then its speed may be slowly increased 
until the regular number of revolutions per minute 
are secured, when the throttle valve should be 
opened wide enough to give full capacity of the 
pipe, and the governor allowed to control the speed. 

The rule for determining the power of any double 
acting engine may be briefly stated as follows: 

Multiply the area of piston, minus one-half the 
area of piston rod, by the speed of piston in feet 
per minute, and by the mean effective pressure. It 
is not proper to take the average pressure for this 
purpose. Divide the product of these three num- 
bers by 33,000 and the quotient is the horse power 
developed. 

If the engine is single acting, calculate the speed 
of piston while the steam is acting on it. If the 



AND THEORY. 57 

steam acts on the head end only, it will not be nec- 
essary to make any deduction on account of the 
piston rod. 

If the engine has two single acting cylinders, cal- 
culate the piston speed the same as for one double 
acting cylinder, and proceed as before. If the 
steam acts on the head end of both cylinders, it will 
not be necessary to deduct one-half the area of pis- 
ton rod from the area of piston, as in the case of an 
ordinary double acting engine. 

There is but one way to determine the mean 
effective pressure of an engine while in service, and 
that is by means of the steam engine indicator. 
There are ways of calculating what this should be 
theoretically, but these rules are based on the 
assumption that all of the conditions are perfect, 
which is seldom or never the case. If the admis- 
sion line was square with the atmospheric line, the 
steam showing no evidence of wire drawing, the 
actual point of cut off and clearance known, the 
expansion line a perfect hyperbola, there was no 
back pressure, or if the actual back pressure was 
known, and there was no compression, then we 
could calculate the mean effective pressure without 
an indicator, but until all of the conditions are 
known this instrument will be in demand. 

It is possible to secure a diagram that will show 
a mean effective pressure corresponding to that 



58 



ENGINEERING PRACTICE 



secured by a theoretical calculation, but while this 
may seem to prove accuracy in measuring and cal- 
culating, it is quite possible that an imperfection 
in one part may be offset by a fault in another part, 
in order to show this result. 




A CONDENSING ENGINE AND ACCESSORIES. 

The boiler feed pump is on a level with the 
engine, the feed water heater is between the engine 
and the independent jet condensingapparatus, which 
is set lower than the engine. 



AND THEORY. 59 



CHAPTER 8. 



THE STEAM ENGINE INDICATOR. 

The steam engine indicator is an instrument for 
determining the mean effective pressure of an 
engine, and it resembles a recording steam gage. 
Where a recording gage is attached to a boiler it 
registers the steam pressure for a certain length of 
time. Where an indieator is attached to an engine 
it registers the steam pressure for a certain length 
of time, the only difference being that in the former 
case, the time is usually much longer than in the 
latter. In the case of the boiler the diagram may 
record the variations in pressure during 12 hours> 
or for a week, while with the engine the changes in 
pressure during one revolution of the fly wheel is 
all that is necessary, as a rule. It is absolutely 
necessary, however, that not only the changes in 
pressure be considered, but the exact time that 
these changes take place enters into the calculation 
as an important item. 

The diagram at the end of this chapter shows 
several defects in valve setting, which may be ex- 



60 ENGINEERING PRACTICE 

plained as follows. The horizontal line at the bot- 
tom is the atmospheric line, and if we lay a small 
square on this line, we shall find that the admission 
line is not square with it, but that it leans in the 
direction in which the piston was traveling when 
the diagram was taken, thus proving that the steam 
valve was not open at the beginning of the stroke 
as it should have been. The steam line is not par- 
allel to the atmospheric line, but falls as the piston 
advances, showing that the full pressure is not 
maintained, but that the steam is wiredrawn. The 
point of cut off is not clearly defined, showing that 
the valve does not close as rapidly as good practice 
calls for. 

The expansion line is higher than it should be, 
which tells us that more steam* is admitted after the 
cut off takes place, or in other words the valve 
leaks. The loop at the right show r s that the pres- 
sure does not fall at the end of the stroke as it 
should. The rise indicates that the steam is not 
released at the proper time, but the exhaust valve 
remains closed until the piston has traveled a por- 
tion of the return stroke, when it is opened and the 
pressure falls. As it does not fall to the atmos- 
pheric line, it shows that there is some back pres- 
sure above the atmosphere. The sharp corner at 
the left shows us that the exhaust valve does not 
close as soon as it should in order to shut in some 



AND THEORY. 6l 

of the exhaust steam, and provide a cushion for the 
piston. 

This demonstrates that in order to give correct 
readings, the indicator must be attached to the 
engine in such a way as to cause the irregular 
motion of the cross head to be transmitted to the 
drum of the indicator. This may be accomplished 
by means of a pendulum suspended directly over 
the middle of the travel of that part of the cross 
head to which it is attached, or a pantograph may 
be used for this purpose, in which case the stand 
should be so located that the cross head will travel 
an equal distance on each side of it. The most con- 
venient way, however, is to use a reducing w^heel 
that is attached directly to the indicator, so that it 
is only necessary to attach a cord to the cross head, 
after having adjusted it to the wheel. 

After a diagram is secured for the purpose of 
determining the power developed by an engine, 
the next step is to determine the mean effective 
pressure shown by it. If no instrument made for 
this purpose is at hand, it may be done by setting 
up lines at right angles to the atmospheric line, 
one at each end of the diagram to be measured, and 
dividing the distance between the two into 10 equal 
spaces, aud measure the distance at each space 
between the steam or the expansion line at the top 
and the counter pressure line at the bottom, with a 



62 ENGINEERING PRACTICE. 

scale which corresponds to the spring used in the 
indicator when the diagram was taken. These 
measurements should be taken directly in the center 
of each space in order to secure a correct average. 
Add the results of the ten measurements together, 
divide the sum by ten, and the result will be the 
mean effective pressure. Although any number of 
spaces may be laid off for this purpose, it is not 
advisable to make the number less than ten, and 
with some diagrams it would be better to make it 
twenty, remembering that the sum of the measure- 
ments must be divided by the number of measure- 
ments' taken. The gre*ater number of divisions is 
recommended in cases where the lines of the dia- 
gram are very irregular, because by their use a bet- 
ter average is secured. 

If the expansion line falls below the atmospheric 
line in the case of a non-condensing engine, form- 
ing a loop, the sum of the measurements of that 
part which is below the line must be subtracted 
from the sum of those above it, and the remainder 
divided by the total number of measurements taken. 

The mean effective pressure may be determined 
by means of any accurate rule or scale, in which 
case the average height in inches must be multi- 
plied by the number of the spring in the indicator, 
when the diagram was taken. 



AND THEORY. 63 




A DEFECTIVE INDICATOR DIAGRAM 

(For explanation see Chapter 8). 



A GOOD ENGINEER SHOULD BE 
APPRECIATED. 

The engineer in charge of a steam plant has many 
cares and responsibilities on his mind that are not 
appreciated by the general public, because they do 
not understand them, and some owners of steam 
plants appear equally ignorant on the subject. 
When a faithful and competent engineer has held 
a position for many years, and always has his plant 
ready for use when it is wanted, his services are 
sometimes undervalued, but when a new man takes 
the position and has trouble with the machinery, 
the owner begins to realize that his former engineer 
was more valuable than he supposed. 



64 ENGINEERING PRACTICE 



CHAPTER 



PLANIMETERS, COMPOUND ENGINES, HORSE 
POWER CONSTANTS. 

The process of dividing a diagram into a number 
of spaces, and taking measurements in order to 
determine the mean effective pressure, is a slow 
one — altogether too slow for this age of the world 
— and to shorten it, instruments called planimeters 
have been devised. Among the most prominent of 
these may be found the Coffin, Amsler, Lippincott 
and Willis. Where an engineer has many of these 
diagrams to make calculations for, one of these 
instruments proves to be a great convenience, as it 
will save much time. Full directions for their use 
may be found in catalogues illustrating them, pub- 
lished by manufacturers or dealers. The mean 
effective pressure of both single diagrams should be 
added together, and the result divided by two. 

When we know the mean effective pressure of an 
engine, we multiply the area of piston, speed of 
piston and mean effective pressure together, divide 
the product by 33,000 and the result is the power 
developed, as already explained. 



AND THEORY. 65 

If we have a double engine we proceed in the 
same way with each of them, and add the results 
together, the final sum being the total power of the 
engine. If we have a compound engine each cyl- 
inder may be treated as if it were a separate engine, 
and the results added together. The fact that in 
such an engine the steam is used in one cylinder 
and then exhausted into another, seems to be a con- 
fusing element, but it shouid not be, for the back 
pressure in the high pressure cylinder of a com- 
pound engine is always high, showing that the full 
benefit of the steam has not been realized here, con- 
sequently we are in no danger of calculating on the 
same steam twice. The foregoing statement con- 
cerning a high back pressure applies to a compound 
engine that is properly designed for the load put 
upon it. If an engine of this type is too large, the 
back pressure in the first cylinder is low, and it had 
better be exhausted into the air at once. 

The object in designing and building compound 
engines is not necessarily to get more power, but to 
save steam, which means coal. If more power is 
wanted a larger single cylinder could be built, but 
this might mean a larger consumption of steam, 
while the adoption of a compound engine might 
result in more power being obtained at less cost. 

With a simple engine having a large cylinder, 
and short cut off in order to profit by the expansive 



66 ENGINEERING PRACTICE 

qualities of steam, the condensation is great be- 
cause the initial pressure is high, and the terminal 
pressure is low, or it might be more comprehensive 
to say that the terminal pressure of one stroke is 
low, and the initial pressure of the next one is high, 
thus making a great difference in temperature, 
hence great condensation. Where this difference is 
divided between two cylinders, the condensation is 
much less, therefore the compound engine is eco- 
nomical in the use of steam. 

The horse power constant of a simple engine is 
found by multiplying the area of piston, by its 
travel in feet per minute, and dividing the product 
by 33,000. For illustration let us take a 24 by 48 
inch engine running 70 revolutions per minute. 
24x24 x .7854=452.4 area of piston in square 
inches. 48x2-^12=8 feet travel per stroke, and 
8x70=560 feet per minute. Then 452.4 x 560 
= 253,344. Dividing this by 33,000 shows us that 
7.677 is the horse power constant. To find the in- 
dicated horse power, multiply the horse power con- 
stant by the mean effective pressure. Suppose the 
latter to be 40 pounds, then 7.677 x 40 =307 horse 
power. Where great accuracy is desired, the area- 
of piston rod must be taken into account, and one 
half of it subtracted from the area of the piston. 

Another constant of this kind is found by multi- 
plying the area of the piston by its travel during 



AND THEORY. 6j 

one revolution, and dividing the product by 33,000. 
With the engine before referred to it would be 
452.4 x 8 -T- 33,000 = .10967 To find the horse 
power from this we must multiply it by the num- 
ber of revolutions, and by the mean effective pres- 
sure, and .10967 x 70x40 =307 horse power as 
before. 

Such a rule would be convenient in estimating 
the power of an engine before its exact speed was 
determined, or in places where different speeds are 
employed to meet the requirements of the service. 

The horse power constant of the low pressure 
cylinder of a compound engine, may be found in 
either of the above ways. 

Suppose that the engine we have been consider- 
ing is the high pressure side of a compound engine, 
and the low pressure side has a cylinder 48 inches 
in diameter with the same stroke. Area of cylin- 
der 1,809.56 square inches, and 1,809.56x560^ 
33,000=30.707 which is the horse power constant 
for the low pressure cylinder. 

If the mean effective pressure is 10 pounds, then 
30.707 x 10 = 307 horse power. Adding these two 
together we find the total power to be 307 +3°7 = 
614 indicated horse power. 

The intermediate and low pressure cylinders of 
triple and quadruple expansion engines may be 
treated in the same way, whether they are run con- 
densing or non-condensing. 



68 



ENGINEERING PRACTICE 




THE LIPPINCOTT PLANIMETER. 



AND THEORY. 



6 9 




THE WILLIS PLANIMETER. 
O 

TESTING GOVERNORS. 

The governor of a throttling engine and the cut 
off mechanism of an automatic engine, should be set 
so that with the highest available steam pressure on 
the boilers, and the lightest load on the engine, the 
speed of the crank shaft will not be excessive. 
Some engines regulate so closely that the variation 
under extreme conditions is less than 2 per cent, 
while in others it may amount to 5 per cent. 

Engines should be tested for this defect at short 
intervals in regular service, also whenever repairs 
or changes of any kind have been made. The 
practice of lengthening or shortening the rods 
which connect the governor to the cut off mechan- 
ism of a Corliss, or any similar engine, in order to 
increase the speed, is dangerous, because the point 
of cut off, when the balls are in their highest posi- 
tion, may be long enough to cause the engine to 
race, if all of the load is suddenly removed. 



JO ENGINEERING PRACTICE 



CHAPTER 10. 



MORE ABOUT HORSE POWER CONSTANTS. 

CALCULATING THE RATIO OF EXPANSION FOR 
COMPOUND ENGINES. 

When estimating the power of a compound 
engine we may assume that all of the power is 
developed in the low pressure cylinder, and one 
way to do this is to reduce the mean effective pres- 
sure of the high pressure cylinder to its equivalent 
to that of the low pressure cylinder, and add the 
two together. In other words, we may take a por- 
tion of the mean effective pressure of the high pres- 
sure side, and add it to the mean effective pressure 
of the low pressure side, then multiply the sum by 
the horse power constant of the low pressure cylin- 
der, and the result will be the total power of the 
engine. 

The number by which to divide the mean effec- 
tive pressure of the high pressure side, is found by 
dividing the area of the large piston by the area of 
the small piston. 



AND THEORY. Jl 

With the engine referred to in the previous chap- 
ter it is 1,809.56-^452.4=4. We have assumed 
the mean effective pressure to be 40 in one cylinder 
and 10 in the other. Then 40 -=- 4 — 10 and 10 -f- 
10 = 20 pounds mean effective pressure for the com- 
bined cylinders. The horse power constant of the 
low pressure cylinder is 30.707 and 30.707 x 20 = 
614 horse power as before. 

The foregoing may be applied to any compound 
engine, if the data for its particular case are used 
in place of that assumed in the above illustration. 

In this calculation the strokes of both sides are 
assumed to be equal, but occasionally an engine is 
built where they are different, and in such a case 
the cubical contents of the cylinders must be used 
instead of the areas of the respective pistons. 

The ratio of expansion for each cylinder of a 
compound engine is found in the same way that it 
is for a simple engine, namely, by dividing the 
whole stroke in inches by the number of inches 
traveled by the piston when the cut off takes place. 

If greater accuracy is desired the clearance must 
be added to the stroke, and also to the distance 
traveled ap to the point of cut off. Where the stroke 
is 48 inches, and the cut off is at 12 inches, not con- 
sidering the clearance it would be 48 -7- 12 =4 which 
is the iatio of expansion. Calling the clearance 
equal to .5 inch, the example would be 48.5 -f- 12.5 



72 ENGINEERING PRACTICE 

= 3.88 It is customary to omit the clearance in 
these calculations. 

If the stroke is not given in inches, and the point 
of cut off is stated in decimal parts of the stroke, 
then call the stroke 1 and divide it by the given 
decimal. The quotient will be the ratio of expan- 
sion. Suppose that the cut off takes place at .25 
of the stroke, then 1 -f- .25 = 4. 

When we wish to determine the combined ratio 
of expansion for a compound engine, or in other 
words the total number of times that the steam is 
expanded, the ratio for one cylinder must be multi- 
plied by that of the other. It will not answer to 
add them together, for the simple reason that the 
result will not be correct. In the case of an engine 
whose cylinders are as 1 is to 4, the volume of the 
high pressure cylinder is equal to the volume of the 
lowpressure cylinder uptoone-quarterstroke. When 
the low pressure piston has advanced to one-half 
stroke the volume is double that of the high pres- 
sure cylinder. At three-quarters stroke it is three 
times as great, and at full stroke it is four times as 
large, hence the expansions must be multiplied 
together instead of added. If it is 4 for each cyl- 
inder, then 4x4= 16 for the whole engine. 

Another rule for ascertaining the combined ratio 
of expansion is as follows: 

Divide the volume of the low pressure cylinder 
by the volume of the high pressure up to the point 
of cut off, and the quotient will be the combined 



AND THEORY. 73 

ratio of expansion. In the case of an engine such 
as we have been considering, with cylinders 24 and 
48 inches in diameter, with a stroke of 48 inches, 
cutting off at one-quarter stroke, the calculation is 
as follows: 

The area of a 24 inch circle is 452.4 square 
inches, and the cut off is at 12 inches, therefore 
452.4 x 12 == 5,428.8 cubic inches, which is the vol- 
ume of the high pressure cylinder up to the point 
of cut off. The area of a 48 inch circle is 1,809.56 
square inches, and 1,809.56x48=86,858.88 cubic 
inches, which is the volume of the low pressurecyl- 
inder. 86,858.88 -~ 5,428.8=16 which is the com- 
bined, or total ratio of expansion as before. 

The actual combined ratio of expansion may be 
found directly from the indicator diagram as 
follows: 

Divide the absolute initial pressure of the high 
pressure cylinder, by the absolute terminal pres- 
sure of the low pressure cylinder, and the quotient 
will be the actual combined ratio of expansion. 

Suppose that the initial pressure by the gage is 
160 pounds, making the absolute pressure 175 
pounds, and the absolute terminal pressure is 11 
pounds, then 175 -f- 11 = 16 expansions. 



Examine the lacing in your main belt every night, 
and renew it before it fails when power is wanted. 



74 



ENGINEERING PRACTICE 




A CROSS COMPOUND ENGINE. 

THIS SHOWS A CONVENIENT ARRANGEMENT OV 
THE BY-PASS VALVE. 



A GOOD PLAN. 

As it is practically impossible to secure natural 
water for steam boilers that will not form scale on 
the sheets and tubes, it becomes necessary in many 
cases, to blow down one gage of water each day. 
Thebest time to do this is in the morning, when the 
fire is banked, because the sediment has then set- 
tled to the lower parts of the boiler, whence it will 
pass out with the water, and if it is impossible to 
close the blow off valve or cock, for any cause, the 
boiler will not be burned, as it would be if the fire 
was burning briskly. 



AND THEORY. 75 



CHAPTER II. 



RECEIVERS. CROSS AND TANDEM COMPOUND 

ENGINES. 

The term " receiver," when applied to a com- 
pound engine, refers to a steam drum between the 
high and low pressure cylinders, the former ex- 
hausting into it, and the latter taking steam from 
it. The size of the receiver, when compared with 
either of the cylinders, varies greatly in the differ- 
ent types of engines, ranging from the volume of 
the high pressure cylinder in some cases, to five 
times this volume in others. 

With this great variation in practice, and good 
results being obtained from all of them under vari- 
rious conditions, it is impossible to give any rule 
that will fix the capacity of receivers for different 
engines. The comparative position of the cranks 
will affect the results, but the larger the receiver 
is, the less the pressure in it will fluctuate. The 
condensation of steam is greater in a large than in 
a small receiver, and as this is an important factor, 
it limits the capacity of them. 



76 ENGINEERING PRACTICE 

It is equally difficult to fix the comparative sizes 
of cylinders for compound engines, when run con- 
densing or otherwise, as different builders present 
a variety of sizes, ranging from a proportion of 1 to 
3, to 1 to 5 in general practice, and even a propor- 
tion of 1 to 7 being favored in some cases. Those 
who favor the latter combination claim that it has 
never been proved to be wasteful of steam in prac- 
tice, therefore there is no good reason for rejecting it. 

The plan of converting a simple engine into a 
compound by adding another cylinder may be a 
good one, and it may be otherwise, for it depends 
on the conditions under which the engine is run. 
If the simple engine is underloaded, it is obvious 
that the cut off will be short and the terminal pres- 
sure low, so that there will be little force left in the 
steam when it is exhausted from the cylinder. If 
another cylinder should be added under such con- 
ditions it would be a detriment, for instead of assist- 
ing in doing work, the low pressure piston 
would be an additional load on the high pressure 
side. If the simple engine is overloaded it will pay 
to make further use of the steam rather than to 
exhaust it into the atmosphere. 

A tandem compound engine is one in which one 
cylinder is located directly behind the other, both 
pistons being attached to one piston rod. With 
this engine but one crank, cross head and one pair 



AND THEORY. 77 

of guides are necessary. It occupies less room than 
a cross compound engine, and its first cost is less. 
It cannot be so conveniently operated, however, 
for it is liable to stop on the center after steam has 
been shut off, the same as a simple engine is, and 
when made in large sizes, as they frequently are, 
this is an objection. If one cylinder becomes dis- 
abled from any cause, it is seldom practical to dis- 
connect it and use the other until repairs can be 
made. 

The cross compound engine consists of two cyl- 
inders, one larger than the other, each having its 
own valve gear, the pistons of which drive separate 
cranks on one crank shaft. It occupies a little 
more room than the tandem, and its first cost is 
somewhat greater where everything else is equal. 
It has the great advantage of not being totally dis- 
abled if an accident happens to one of its cylinders, 
as it is usually practical to disconnect one connect- 
ing rod and run with the other cylinder until re- 
pairs can be made. In this way a portion of the 
works can be kept in operation. 

It is a very convenient engine to handle, for when 
the cranks are set at an angle of 90 degrees, or even 
at 120 degrees, if the high pressure crank stops on 
a center, steam may be admitted to the low pres- 
sure cylinder, and the engine started up, provided 
the valve gear is designed to admit steam full 



78 ENGINEERING PRACTICE. 

stroke. This is accomplished by means of a steam 
pipe of comparatively small diameter, leading from 
the main steam pipe directly to the low pressure 
cylinder. A suitable valve being placed in this 
pipe it may be used at pleasure for this purpose, 
and also for admitting steam to the low pressure 
cylinder when running, if for any reason it is desir- 
able to do so. Such a pipe is called a "by-pass." 

A steeple compound engine is one in which the 
cylinders are placed directly above the crank, as in 
the case of a simple vertical engine. The low pres- 
sure cylinder is usually placed next to the frame, 
and the high pressure above it. It possesses the 
same advantages that any vertical engine does, in 
occupying but a small floor space, and as the pis- 
tons do not rest on the bottoms of the cylinders, 
the friction and wear are possibly somewhat less. 
Some of these engines have proved to be very 
efficient. Their disadvantages are more in the line 
of inconvenience in making repairs and adjustments, 
and their unconventional general appearance rather 
than any real objection that can be mentioned. 

However, engineers always have a choice in such 
matters, and the author is no exception to the gen- 
eral rule, but does not hesitate to state his prefer- 
ence for the horizontal, cross compound engine. 
Although many advantages are claimed for vertical 
engines, still it is a significant fact that they are 



AND THEORY, 



79 



still in the minority, and are liable to be for many 
years to come. In marine service the vertical style of 
engine, both simple and compound, has an excellent 
record for economy of fuel, but this is due to favor- 
able conditions which are more frequently found at 
sea than on land, and to these conditions, rather 
than to the particular style of engine, must the 
credit be given. If the load on a horizontal engine 
that is properly proportioned for its load is constant, 
and the proper pressure and quality of steam is 
available, the results will show that it is very eco- 
nomical in the use of fuel. 




A MODERN HORIZONTAL HIGH SPEED TANDEM 
COMPOUND ENGINE. 



8o ENGINEERING PRACTICE 



CHAPTER 12. 



TRIPLE EXPANSION ENGINES. 

The power of a triple expansion engine is deter- 
mined by ascertaining the power developed in each 
cylinder separately, the same as if it w r ere a single 
engine, and adding the results together, as men- 
tioned in a previous chapter, but when taking dia- 
grams from these engines care must be taken to 
secure those that faithfully represent the power 
developed at the same time. It will net answer to 
take a diagram from one cylinder, and then take 
them from the others at convenient seasons, for 
even if one minute elapses between the two opera- 
tions there is no way of knowing whether the results 
are correct or not, taking the engine under normal 
conditions, for the load may have changed in the 
meantime, so that the diagrams will not correctly 
represent the load on the entire engine. 

This may be accomplished by having an indicator 
on each cylinder, and taking diagrams simultane- 
ouslv, but as only one end of each cylinder can be 



AND THEORY. 8l 

indicated at once, (unless two indicators are pro- 
vided for each cylinder), care should be taken to 
get diagrams from corresponding ends, so that 
reliable results may be secured. 

It is quite possible to do this with one indicator, 
provided the cut off mechanism for all of the cylin- 
ders is controlled by one governor, or it may be 
done if the cut off devices for the second and third 
cylinders are fixed, so that the same results will be 
secured from them, provided the conditions in the 
first cylinder are the same. 

A diagram may be taken from the high pressure 
cylinder, and the exact position of the governor 
noted, provided it is of the fly ball type, so as to 
make it possible to do so, and when diagrams 
are taken from the other cylinders, the governor 
must be brought to the same position that it was 
when the first diagram was taken. This will give 
correct results if the boiler pressure is the same in 
both cases. 

The actual combined, or total ratio of expansion 
may be ascertained from the diagrams by dividing 
the initial pressure in the high pressure cylinder, 
by the terminal pressure in the low pressure. 

For illustration, suppose that the initial pressure 
by the gage is 175 pounds, and the terminal pres- 
sure is 7 pounds absolute ; then 175 -f- 15 ~ 7 = 27 
expansions. 



82 ENGINEERING PRACTICE 

If we wish to calculate the ratio of expansion for 
each cylinder separately and from them obtain the 
total ratio, we must multiply the ratiostogether and 
the result will be the total ratio for the engine. 
Suppose that the conditionsare such that the expan- 
sion ratio for each cylinder is 3 and there being 
three cylinders 3x3x3 = 27 expansions. 

In order to illustrate this we may assume that the 
first, or high pressure cylinder is 11 inches in diam- 
eter, and the cut off takes place at one-third of the 
stroke, making the expansion rate 3. 

If the second, or intermediate cylinder is three 
times the area of the first, or 19 inches in diameter, 
aud the cut off takes place at one-third stroke, the 
expansion rate will be 3 for this cylinder, and for 
the two it will be 3 X3 =- 9. 

If the third, or low pressure cylinder is three 
times the area of the intermediate, or 33 inches in 
diameter, and the cut off takes place at one-third 
stroke, the expansion rate for this cylinder will be 
3 and the combined ratio Avill be 3 x 3 x 3 = 27. 

In order to calculate the total expansion rate, or 
ratio, without bringing the intermediate cylinder 
into the calculation, proceed as follows: 

Divide the volume of the low pressure cylinder, 
by the volume of the high pressure cylinder up to 
the point of cut off, and the quotient will be the 
total ratio of expansion. If the engine that we 



AND THEORY. 83 

have just been considering has a stroke of 30 inches, 
then the volume of the low pressure cylinder is 
33 X33 x .7854 x 30 = 25,650 cubic inches. The 
volume of the high pressure cylinder up to the 
point of cut off is nxnx .7854 x(30 -7- 3) = 950 
cubic inches. Then 25,650 -7- 950 =27 as before. 

All triple expansion engines are not constructed 
with three cylinders, however, for some of them 
have four. The advantage of this is as follows: 

If we want to design an engine larger than the 
one that we have been considering, we may make 
the first cylinder 30 inches in diameter, the second 
52 inches and the third 90 inches, and still preserve 
the same proportions nearly. 

But a 90 inch cylinder is a lather large size and 
it may be advisable to avoid its use, especially if it 
is to be a horizontal engine. If we divide the area 
of it into tw r o equal parts, and make two low pres- 
sure cylinders each 63.75 inches in diameter, we 
shall secure the desired result with much smaller 
cylinders. This makes a more symmetrical engine 
and will give good results in practice, but it has a 
greater number of parts, or in other words, it is 
more complicated than the three cylinder triple 
expansion engine. 

To determine the total ratio of expansion for this 
engine, divide the cubical contents of the two low 



84 



ENGINEERING PRACTICE 



pressure cylinders by the contents of the high pres- 
sure cylinder up to the point of cut off. 

Assuming the stroke to be 60 inches, each low 
pressure cylinder contains 191,520 cubic inches or 
383,040 cubic inches for both. The high pressure 
cylinder, up to the point of cut off, which is assumed 
to be at one-third stroke, contains 14,136 cubic 
inches. Then 383,040 -r- 14,136 = 27 expansions. 




A TRIPLE EXPANSION ENGINE. 

This illustrates a modern high speed, triple ex- 
pansion engine, with four cylinders, arranged as a 
double tandem compound, showing a very compact 
and convenient arrangement of the several parts. 
As the cranks are set at right angles, the motion 
imparted to the crank shaft is uniform, therefore 
very desirable for electric lighting. 



AND THEORY. 85 



CHAPTER 13. 



QUADRUPLE EXPANSION ENGINES. VARIOUS TYPES 

OF CONDENSERS. 

A quadruple expansion engine is one in which 
the steam is expanded and used in four cylinders. 
When speaking of compound, triple or quadruple 
expansion engines, it is proper to state whether 
they are run condensing or not. It is customary to 
assume that a condenser is employed, for it effects 
a greater saving with them than with a simple 
engine, but at the same time if a quadruple engine 
is used, strictly speaking it does not mean that it is 
run condensing, for if it is, then the machine should 
be referred to as a quadruple expansion condensing 
engine, and this applies to the others mentioned. 

The ratio of expansion is found by multiplying 
the number of expansions in each cylinder together, 
as in the case of the compound or the triple expan- 
sion engine. 

To determine the actual ratio in every day prac- 
tice, divide the initial pressure of the high pressure 



86 ENGINEERING PRACTICE 

cylinder by the terminal pressure, both absolute, of 
the low pressure cylinder. 

There are several forms of condensers used in 
connection with these engines, as follows: 

The jet condenser is so constructed that a pump, 
which is commonly called an air pump, draws the 
exhaust steam, water and air from the engine cyl- 
inder, and also pumps water from a river or other 
source of supply, bringing them together in the 
condenser. As the exhaust steam meets this jet of 
water it is condensed, and usually allowed to run 
to waste, except a small portion of it that is used 
for boiler feeding. 

A short distance from the condenser, a compara- 
tively small well is provided, into which the con- 
densed steam and water flows on its way to the sewer 
or river, and this is called the hot well, for out of 
it the boiler feed pump takes its supply. 

A surface condenser resembles a small tubular 
boiler in some respects, but the tubes are usually 
made of brass. The exhaust steam to be condensed 
is pumped through the tubes, while the cold water 
fills the body of the condenser, or the steam may be 
drawn through the body of it, while the water cir- 
culates through the tubes. The pump which 
draws, or forces water through the condenser, is 
called the circulating pump. An air pump is used 
to create a partial vacuum in the exhaust pipe. 



AND THEORY. 87 

The jet condenser system is simple in construc- 
tion, and low in first cost, but comparatively pure 
water must be used with it, as a portion of it is 
used for boiler feeding. 

The surface condensing system is more compli- 
cated and consequently more costly, as it requires 
two pumps and a more elaborate condenser, but 
salt or impure water may be used where it is em- 
ployed, as the condensed steam does not come into 
contact with it, and consequently the feed water for 
the boilers remains pure. As all of the water 
resulting from the condensation of steam is pumped 
back into the boilers, precautions must be taken 
to remove the cylinder oil from it. 

With either of these systems, or any other that 
is in use, a large quantity of water is needed for the 
condenser, where it is used but once and then 
allowed to go to waste. The quantity varies from 
20 to 30 times the amount needed to generate the 
steam, but if it is allowed to run into a pond and 
remain there until cool, it may be used over again. 

Sometimes this hot water is pumped into the air 
in jets similar to fountains on a large scale, in order 
to facilitate the cooling process, and in other places 
where floor or ground space is very valuable, cool- 
ing towers are employed, in which the water is 
pumped to the top and allowed to fall in thin sheets, 
being met by a current of air which is forced up- 



88 ENGINEERING PRACTICE 

ward by a fan. Where this plan is adopted, it is 
claimed that no more water is needed to run con- 
densing than non-condensing without it, after the 
tower is once supplied with sufficient water to start 
with. 

Sometimes siphon, or injector condensers are 
employed, and the principle on which they operate 
is to utilize the drafting power of a column of fall- 
ing water to create a partial vacuum in the exhaust 
pipe of an engine, and also to raise the water nec- 
essary for condensation. They give good results in 
practice, are simple in construction, easy to oper- 
ate and their first cost is not excessive. 

We are sometimes told that condensing engines 
are objectionable because they require more intelli- 
gent supervision, and consequently the salary of 
the engineer will be more than where they are not 
used. This is poor policy, because an intelligent 
engineer should be employed in every case, and a 
fair salary paid for good service, as it will prove to 
be a paying investment. 

Some of the engines in mills and factories could 
not be run condensing, for the stuffing boxes and 
joints are in such poor condition as to make it 
impossible to maintain sufficient vacuum to be prof- 
itable, but this fact does not prove that it is eco- 
nomical to run plants in this condition. 



AND THEORY, 



8 9 



In many cases it would pay to remodel old plants 
that are now run in a wasteful condition, or throw 
them out entirely, and install new ones of modern 
design. With the best available engineer in charge, 
more satisfactory power would be secured at less cost. 




i/)iil)i»iiiiimimiiiiwii">»Vii 



SURFACE CONDENSER AND COOLING TOWER. 

This illustrates a surface condenser which may 
be used to good advantage where there is an abun- 
dant supply of impure water, as none of it is used to 
feed the boilers. It also shows a cooling tower, by 
the aid of which the same water may be used many 
times over. This makes it practical to use pure 
water from the city mains in cases where it is desired 
to do so, for after the tower is once filled it requires 
no more than is necessary to feed the boilers of a 
non-condensing plant. The fan is driven bv an 
independent engine. 



90 ENGINEERING PRACTICE 



CHAPTER 14, 



PUMPING MACHINERY. CALCULATING THE DUTY 
OF A PUMPING ENGINE. 

A cubic foot of pure w r ater at a temperature of 
39 c Fah., at which point it reaches its greatest den- 
sity, weighs 62.425 pounds, and at 62 which is 
called the standard temperature, it weighs 62.355 
pounds, but for all ordinary calculations its weight 
is taken at 62.5 pounds for all temperatures that 
we find in practice where artificial heat has not been 
applied. There are 7.5 gallons in a cubic foot, and 
by diYiding 62.5 by 7.5 we find that one gallon 
weighs 8.3 pounds, and as there are eight pints in a 
gallon it is sometimes said that 

11 A pint weighs a pound 
The world around," 

which is nearly correct but not absolutely so. This 
refers to the United States standard gallon of 231 
cubic inches. 

A foot pound is one pound in weight raised one 
foot high, therefore if we raise one gallon of water 



AND THEORY. 91 

one foot high, we have developed 8.3 x 1 = 8.3 foot 
pounds, and if we raise it 100 feet high we have 
developed 8.3 x 100 = 830 foot pounds. 

The duty of a pumping engine is usually rated 
by the number of foot pounds it will develop while 
100 pounds of coal are burned under the boilers, 
provided it is desired to take into consideration the 
efficiency of the boilers and the engine together, 
but if the engine is to be taken separately, the duty 
is based on the number of foot pounds developed 
while a given number of pounds of steam are passing 
through the engine. This number is frequently 
taken at 1000, for if the boilers evaporate ten 
pounds of water for each pound of coal burned, it 
is equivalent to burning 100 pounds of coal under 
the boilers. 

If all of the pumping engines in use were raising 
water to a given height under exactly similar con- 
ditions, then all that would be necessary to do 
would be to ascertain the number of gallons pumped, 
and make the standard allowance for friction, when 
the duty would be known, but inasmuch as the 
engine builder rates his machine by the foot pounds 
developed in the water cylinder, we must take into 
account the number of gallons raised, the height 
to which it is elevated, the height of the source of 
supply, and the friction of the water in the pipes. 



92 . ENGINEERING PRACTICE 

When the height in feet of a column of water is 
known, we may calculate its pressure by dividing 
by 2.304 If it is 125 feet high, then 125 -f- 2.304 = 
54.3 pounds. If the pressure is given and we wish 
to know the height, multiply the pressure by 2.304 
and 54.3x2.304=125 feet. Therefore if the res- 
ervoir is 125 feet above the pump, the pressure on 
the water piston due to the height of the column of 
water will be 54.3 pounds, but we cannot calculate 
on that alone, because the friction of the water in 
the pipes must be accounted for, and if there was 
any way of calculating it definitely we could add 
the two together and the sum would be the total 
pressure, but from the above it is plain that the 
easiest and best way is to attach a gage to the water 
pipe close to the water cylinder, and the pressure 
that it indicates tells us the resistance per square 
inch at once. 

If the source of supply is above the pump, the 
pressure in the supply pipe must be subtracted from 
the pressure in the delivery pipe, and if the supply 
is below the pump a vacuum gage may be attached 
to the suction pipe, and the quotient found by 
dividing the vacuum in inches by 2.04 must be 
added to the pressure in the delivery pipe. 

In order to determine whether this resistance is a 
constant factor or not, an indicator should be 



AND THEORY. 93 

applied to the water cylinder of the pump, just as it 
is to the steam cylinder of an engine. 

When calculating the horse power of an engine, 
we multiply the area of the piston by its travel in 
feet per minute, and by the mean effective pressure, 
the result being the number of foot pounds devel- 
oped. We may treat the pumping engine in a 
similar way by multiplying the area of the water 
piston by the distance that it travels while ioo 
pounds of coal are burned, and by the resistance in 
pounds per square inch. The result will be the 
foot pounds developed per ioo pounds of coal. 

The time that it takes to burn ioo pounds 
of coal may be found by dividing the number of 
minutes covered by the test, by the total pounds 
of coal burned, and multiplying the result by ioo. 
Suppose that during a test lasting 9.5 hours four 
tons of coal, containing 2,240 pounds each are 
burned. How long did it take to burn 100 pounds? 
9.5 hours equals 570 minutes, and four tons of coal 
makes 8,960 pounds. Then 570 -=- 8,960 =.0636 
minutes required to burn one pound, and .0636 x 
100= 6.36 minutes required to burn 100 pounds. 

If we have a pumping engine whose water piston 
is 24 inches in diameter its area will be 24 x 24 x 
.7854=452 square inches. If the stroke is 54 inches 
and it makes 50 single strokes per minute, the 
travel of the piston will be 54 x 50 ~ 12 = 225 feet 



94 ENGINEERING PRACTICE 

per minute, and for 6.36 minutes it will be 
225 x 6.36 = 1,431 feet, which is the piston speed 
for this calculation. We will assume the water 
pressure to be 85 pounds, and our calculation 
then is 452 x 1 ,431 x 85 = 54,979,020 foot pounds. 
If it is a duplex pump and both pistons make full 
strokes, we multiply this by 2, which gives 
109,958,040 foot pounds developed per 100 pounds 
of coal. 

Great improvements have been made in the past 
few years, so that at present these machines are 
very efficient, and although their first cost is large, 
it proves to be a good investment. 

The load on a pumping engine is constant, or 
nearly so, for a given piston speed, and as this load 
may be estimated in advance, an engine can be 
designed accordingly, thus securing economy in 
fuel, for the steam pressure can usually be varied 
to suit unforeseen conditions. 

o 

VERTICAL CROSS COMPOUND PUMPING ENGINE. 

The illustration on the opposite page shows a 
vertical, cross compound pumping engine with one 
high pressure and two low pressure cylinders. 
This design makes it possible to deliver a nearly 
constant stream of water into the main, thus avoid- 
ing the shocTcs and vibration inseparable from the 
single engine type. 



AND THEORY, 



95 




•»■ * 



-^■=j!- u --?--:,-- 



VERTICAL CROSS COMPOUND PUMPING ENGINE. 



g6 ENGINEERING PRACTICE 



CHAPTER 15. 



MORE CALCULATIONS CONCERNING PUMPING 

ENGINES. 

Where the duty of a pumping engine is based 
on the time that it requires for 1000 pounds of 
steam to pass through the cylinders, it is not nec- 
essary to weigh the coal, nor give particular atten- 
tion to the way in which the boilers are run, but 
the water used for making steam must be weighed, 
and the time that it requires for 1000 pounds of it 
to pass through the cylinders carefully noted. 
This may be determined by the following rule : 

Divide the total number of minutes covered by 
the test, by the total pounds of water evaporated, 
and multiply the result by 1000. The product 
will be the required time. The water that passes 
off with the steam must be deducted from the 
amount fed to the boilers. 

For illustration, suppose that during a test last- 
ing nine hours and fifteen minutes, 91,840 pounds 
of water are fed to the boilers, but 5 per cent of it 



AND THEORY. 97 

passes off with the steam without being evapo- 
rated. 91,840 x .05 = 4,592, and 91,840 — 4,592 = 
87,248 pounds evaporated. Nine hours and fifteen 
minutes are equal to 555 minutes. Then 555 -=- 
87,248 = .00636 and multiplying this by 1000 
shows us that 1000 pounds of steam will pass 
through this engine in 6.36 minutes. 

This is the same length of time that it required 
to burn 100 pounds of coal in the case of the engine 
mentioned in Chapter 14, and if, for illustration, 
we take the same engine here, the calculation 
and resulting duty will be the same. The pounds 
of water in this case is found by assuming that 
four tons, or 8,960 pounds of coal were burned dur- 
ing the test, and for each pound of coal burned 
10.25 potmds of water were fed into the boilers* 

A duty of 100,000,000 foot pounds is considered 
a very good result in a pumping engine, but while 
many fail to show such efficiency, others exceed it. 
One that was designed several years ago by that 
eminent engineer, George H. Corliss, has greatly 
exceeded this in actual practice. It is a cross com- 
pound engine, with the regular Corliss cylinders 
and valve gear. Steam is used at 142 pounds abso- 
lute pressure, and the ratio of expansion varies 
from 15 to 20. This is one of the first pumping 
engines built that showed such excellent results, 
and is located ar Pawtucket, R. I. A large bal- 



98 ENGINEERING PRACTICE 

ance wheel is mounted on a suitable crank shaft 
located above the water cylinders, and a bell crank 
lever and suitable links connect the balance wheel 
to the reciprocating parts of the engine, thus ena- 
bling it to pass the dead centers. 

A crank and fly wheel pumping engine has also 
been put on the market by The Geo. F. Blake Man- 
ufacturing Co., which is very efficient. 

The Edward P. Allis Co. build a vertical triple 
expansion pumping engine, with crank and fly 
wheel, that shows very good results in practice. 
The fly wheel, or balance wheel arrangement is, 
however, of necessity, a somewhat cumbersome 
affair, and to overcome this objection, and provide 
other good features, the xi High Duty Attachment^ 
is used on the Worthington pumping engines. It 
consists of a pair of oscillating cylinders in which 
plungers work, that are connected to the cross 
heads on the piston rods which are common to the 
steam and water cylinders. The pressure acting 
on these plungers, opposes the action of the engine 
from the beginning of the stroke in a gradually 
decreasing ratio, until half stroke is reached, when 
it is neutralized by the position of the plungers. 

During the latter half of the stroke it assists the 
action of the engine, more effectively as the end of 
the stroke is approached, thus enabling steam of a 
high pressure to be used to a good advantage, by 



V<; 



AND THEORY. 99 

cutting off short and utilizing the benefits of expan- 
sion, which is the chief object in adopting the 
device. 

Pressure is furnished to these plungers from an 
accumulator, or a reservoir, and this in turn receives 
it from the water main. The pressure of the 
main is multiplied in the lower part of the accu- 
mulator by means of two pistons connected by a 
rod, and working in vertical cylinders, the upper 
piston being much larger than the lower one, hence 
the multiplication of pressure. As a body of water 
is not elastic, some means must be provided for 
cushioning the accumulator, and this is done by 
pumping air into it with a small pump provided 
for the purpose. 

This attachment possesses one great advantage 
in case the water main bursts. With a fly wheel 
and fixed cut off without a throttling governor, if the 
main bursts, thus relieving the engine of its load, 
the speed is increased at once, so that if the engi- 
neer is not at hand to immediately shut off the 
steam, the engine may be wrecked. If the same 
accident happens to a high duty engine, as above 
described, it stops at once, because the release of 
the pressure in the mains relieves the plungers of 
their motive power. Such accidents seldom hap- 
pen, but when they do the results are disastrous, 
therefore every precaution should be taken to pre- 
vent them. 

LofC. 



ICO 



ENGINEERING PRACTICE 



An engine of this type, located at New Haven, 
Conn., developed a duty of 116,000,000 foot pounds 
at a carefully conducted trial, exceeding the guar- 
antee of its builder by 11,000,000 foot pounds. 




<JT 



znzn: 



. , i . 1 



I_j 



COMPOUND CONDENSING DUPLEX PUMPING ENGINE, 

WITH HIGH DUTY ATTACHMENT BETWEEN 

THE STEAM AND WATER CYLINDERS. 



CAPITAL. 
An engineer's reputation is his capital, there- 
fore it should be carefully guarded at all times, 



AND THEORY. IOI 



CHAPTER 16. 



HYDRAULIC PUMPS. BOILER FEEDERS AND TANK 

PUMPS. DATA CONCERNING PUMPING 

MACHINERY. 

When we speak of a hydraulic pressure pump, it 
refers to a type of pump made to operate against 
a much greater pressure per square inch than the 
steam pressure which drives it. This is made pos- 
sible by having a larger steam piston, when com- 
pared with the water piston, than would otherwise 
be required. The pressure that a pump will oper- 
ate against may be calculated as follows : 

Multiply the area of the steam piston by the steam 
pressure acting on it, and divide by the area of the 
water piston. This will give the pressure that 
will equalize the forces, and in order to allow the 
pump to operate, an allowance in the water pres- 
sure must be made according to conditions. Twen- 
ty-five per cent will be necessary in some cases. 

For illustration, suppose that the steam piston 
is 10 inches in diameter, the pressure 90 pounds, 



102 ENGINEERING PRACTICE 

and the water piston 2 inches in diameter. The 
area of the steam piston is 10 x iox .7854 = 78.54 
square inches, and 78.54 x 90 = 7,068 pounds. The 
area of the water piston is 2 x 2 x .7854 = 3.1416 
square inches. 7,068 -5- 3.1416 = 2,249 pounds. 

If we make an allowance of 25 per cent, then 
2,249x^5 = 562 and 2,249 — 562=1,687 pounds 
hydraulic pressure. By increasing the compara- 
tive area of pistons, almost any pressure may be 
secured, for pumps are in operation daily working 
against more than 10,000 pounds to the square inch. 
Boiler feed pumps are designed with a larger water 
piston, when compared with the steam piston, than 
the above, as the difference in pressure is not so 
great, for they are usually calculated to work 
against the same pressure that drives them, plus 
the friction. 

The steam pressure required to drive a boiler 
feed pump may be calculated as follows: 

Multiply the area of the water piston by the 
pressure in the boiler, plus 50 per cent for friction 
and necessary difference in pressure to allow the 
pump to run at the required speed. Divide the 
product by the area of the water piston. 

For illustration take a pump with a steam piston 
10 inches in diameter, and a water piston 6 inches, 
with a boiler pressure of 80 pounds. The area of 
a 6 inch water piston is 28.27 square inches. 50 



AND THEORY. IO3 

per cent of 80 is 40 and 80+40=120. Then 28.27 
x 120 = 3,392.4 The area of a 10 inch steam piston 
is 78.54 square inches and 3,392.4 -5- 78.54 = 43 
pounds. This is a light pressure, but the pump 
works better and proves more durable where a good 
margin is allowed. 

A tank, or light service pump, is made with 
steam and water pistons of the same diameter, or 
with but slight difference either way, as they are 
not intended to work against heavy pressures. 

To determine the diameter of water piston suit- 
able for a given steam piston, when both steam and 
water pressures are known, proceed as follows: 

Multiply the area of the steam piston by the 
available pressure, and divide by the water pres- 
sure plus 50 per cent. Divide by .7854 and extract 
the square root of the quotient. 

For illustration, suppose that we have a pump 

with a 12 inch steam piston, a boiler carrying 90 

pounds pressure, so that 50 pounds are available in 

he cylinder, and the water pressure is 25 pounds. 

The area of a 12 inch steam piston is 113 square 
inches, and 113 x5o = 5,65<>. 25+ (25X -5o)=37.5 
Then 5 650 -=- 37.5 -7- .7854 = 191 tha square rootof 
which is 14 nearly, which is the required diameter 
of the water piston. 

If we wish to determine the diameter of a steam 
piston necessary to drive a water piston of given 



104 ENGINEERING PRACTICE 

area, when the steam and water pressures are 
known, proceed as follows: 

Multiply the area of water piston by the water 
pressure plus 50 per cent, and divide by the steam 
pressure. Divide by .7854 and extract the square 
root of the quotient. 

For example, suppose that the water piston is 10 
inches in diameter, the water pressure 40 pounds, 
and the steam pressure 60 pounds. Then 78.54 x 
(40 + 40 x .50) -=- 60 = 78.54 and 78.54-^.7854 = 
100 the square root of which is 10, therefore the 
steam piston should be 10 inches in diameter. 

Application of the four rules given in this chap- 
ter will enable the engineer to determine the water 
pressure that a pump will work against, the steam 
pressure necessary to run a pump, the required size 
of water piston, and the diameter of steam piston 
for any case. 

A piston pump has a water piston working in a 
cylinder similar to a steam piston and cylinder, with 
a piston rod packed in the same way. 

A plunger pump is fitted with a plunger work- 
ing through a large stuffing box, into the water 
casing of the pump. These are more suitable for 
pumping gritty water than a piston pump. 

A power pump is run by a belt, or by gears from 
the main shaft, or from some countershaft in the 
mill or factory. 



AND THEORY. 105 

Pump manufacturers advise us not to run pumps 
more than 100 feet of piston speed per minute, but 
if their speed does not exceed 50 feet per minute, 
they will last longer and give better satisfaction, 
especially if the water is to be pumped against a 
heavy pressure. 

It is very convenient to calculate the capaci- 
ties of pumps in gallons, at 100 feet piston speed 
per minute, and for this purpose the following rule 
may be used, as it is very nearly correct. 

Square the diameter of the water cylinder and 
multiply by 4. The product is the number of gal- 
lons discharged per minute, and it may be explained 
as follows : 

When it is desired to compute the capacity of a 
pump cylinder, square its diameter, multiply by 
.7854 and by the length in inches. This gives the 
cubic inches per stroke, and to find it for any given 
number of strokes per minute, multiply by the 
number of strokes. With the rule just given it is 
assumed that the piston has traveled 100 feet or 
1 , 200 inches per minute . Multiplying this by the area 

in square inches, or in other words by d x .7854 
gives the cubic inches per minute, and dividing by 
231 reduces it to United States gallons. 
Put into a formula it is as follows : 

d x .7854 xioo x 12 



— gallons per minute. Mul- 



231 



106 ENGINEERING PRACTICE 

tiplying together the figures above the line gives 

2 

d X942 

the following: = gallons per minute, and 

231 

2 4 

proceeding to cancel results as follows: d x^42 



>5* 

d x 4 = gallons per minute. 

While this is not absolutely correct, it is very 
nearly so, for although 231 will go into 942 a frac- 
tion over 4 times, making the result larger, when 
the cubical contents of the rod are taken out, as 
occupying space during one-half of thepiston travel, 
it reduces the result, so that one offsets the other. 

To determine the diameter of water piston that 
will raise a given quantity of water per minute, the 
following rule may be used, assuming the piston 
speed to be 100 feet per minute. 

Divide the number of gallons by 4 and extract 
the square root of the quotient, which will be the 
diameter in inches. 

For illustrationf assume that 100 gallons permin- 
ute are to be raised. Then 100 -=- 4 = 25 the square 
root of which is 5, therefore the water piston should 
be 5 inches in diameter. 



AND THEORY. IO/ 

When a certain quantity of water is to be moved 
per minute, to find the speed of water in the pipe, 
the following rule may be used. 

Multiply the quantity in cubic feet by 144 and 
divide the product by the area of the pipe in square 
inches. 

For illustration, suppose that we wish to move 
25 cubic feet per minute through a 3 inch pipe, 
the area of which is 7 square inches. Then 25 x 
144 -=- 7 = 514.3 feet per minute. 

In order to determine the diameter of pipe re- 
quired to deliver a certain quantity of water per 
minute, multiply the number of cubic feet by 144 
and divide by the velocity of the water in feet per 
minute. Divide by .7854 and extract the square 
root of the quotient. 

Using the above data for illustration results as 
follows : 25 x 144 -7- 514.3 -T- .7854 — 9 the square 
root of which is 3. 

When erecting a pump it is necessary to have a 
perfectly tight suction pipe, that no air may enter 
to partially displace the water, but in some cases, 
where long lines of pipe are carried over hills and 
through valleys, the water under pressure may 
cause pounding in the pipes. Under such condi- 
tions it is beneficial to admit air to the suc- 
tion pipe by means of a small valve provided for 
that purpose. The philosophy of the plan is that 



IOS ENGINEERING PRACTICE 

while water is solid, air is elastic, and the air so 
admitted cushions the water and prevents blows 
that would otherwise cause pounding. 

When the speed of a pump is slow, a small leak 
in the suction pipe may cause trouble, because the 
amount of air admitted is larger in proportion to 
the water than it would be were the speed greater. 

Wheie there is any trouble in locating a leak in 
a suction pipe, it is a good plan to cover the joints 
with a mixture of rosin and tallow. Heat the rosin 
in an iron ladle, and as it melts, add the tallow, 
until the proper proportions are secured. This can 
be determined by taking a small amount of it out 
and spreading it on a piece of iron. If it proves to 
be brittle when cool, and does not adhere to the 
iron, add more tallow, but if it is too soft, add more 
rosin and apply it hot. This forms a perfectly air- 
tight coating that is not expensive, and can be 
easily applied. It can only be used on cold pipes, 
as heat will melt it off. 

When a pump is drafting water on a high lift, 
the exhaust steam may be turned into the suction 
pipe, where it will be condensed, and a partial 
vacuum formed on the exhaust side of the steam 
piston. This idea is patented, therefore its use is 
restricted. 

It is claimed that by this device all of the heat in 
the steam coming from the boiler is returned to it, 



AND THEORY, 



IO9 



but this is a mistake, for some of it disappears in 
developing power, and can never be recovered. 
Every heat unit used in this way is equal to 772 
foot pounds, therefore when 43 heat units disap- 
pear in one minute it is equal to 1 horse power. 




AN ALTITUDE GAGE, 



This indicates the height of water in a tank, 
thus showing when it is nearly full, and preventing 
the necessity of causing it to overflow. 



IIO ENGINEERING PRACTICE 



CHAPTER 17 



INJECTORS. 

An injector is the smallest and most convenient 
device for forcing water into steam boilers, now in 
use. The success attained by the inventors who 
produced some of the earlier types, and later on 
improved their design, has brought many kinds 
into the market at the present time. These may 
be classed under two heads, namely, the lifting and 
the non-lifting injector. 

The lifting injector will take water from any 
source located below the machine, or will take it 
under pressure and deliver it into the boilers. The 
depth from which it will raise water will depend 
upon the steam pressure employed^ but it is not 
practical to lift it more than about 20 feet, so that 
if the supply is much lower than this below the 
boilers, it is advisable to locate the injector so that 
it will not be more than about 20 feet above the 
surface of the supply, as it will force water to any 
reasonable height, and put it into the boilers. 



AND THEORY. Ill 

The non-lifting injector must be supplied with 
water under a head, and answers a very good pur- 
pose for use under this condition, as it is simple in 
construction. 

Injectors may be subdivided into the following 
classes : double tube, single tube, fixed and auto- 
matic. The lines which separate these classes are 
not always strongly defined, as many combinations 
are formed in which the object sought by the 
inventor is not clearly shown, unless it is a desire 
to produce a machine that differs from others in 
use. 

The double tube, lifting injector will continue 
to operate under a widely varying steam pressure, 
as the work is divided between two sets of tubes, 
one of which does the lifting, while the other forces 
water against pressure. They are valuable for use 
in plants where the engineer attends to other duties, 
and consequently allows the pressure in his boiler 
to fluctuate more than he would if allowed to give 
it proper attention. They are also used and highy 
prized in many of our best and most carefully oper- 
ated plants. 

Some of the single tube injectors lift very well, 
but a slight variation in the steam pressure will 
stop their operation, and unless they are automatic 
in action, the process of starting them must be 
repeated. This applies to the fixed injectors also. 



112 ENGINEERING PRACTICE 

The automatic or re-starting injector is usually 
fitted with but a single set of tubes, although all 
single tube injectors are not automatic. The auto- 
matic injector has grown very rapidly in the favor 
of engineers, owing to its peculiar operation, for 
when steam is admitted to it, water will be taken 
from a tank, or under pressure, at pleasure; then, 
as soon as the valve in the feed pipe is opened, the 
water will be forced into the boiler, for there is no 
overflow valve to close. 

After it is started, if the steam pressure rises, it 
will continue to work, but the temperature of the 
feed water will be raised. It is possible to raise 
the pressure so high that the water admitted by an 
ordinary injector will not condense it, and thus its 
operation will be stopped, but this does not apply 
to general practice with an injector in good order. 
If the steam pressure falls, less water will be deliv- 
ered to the boilers, but the injector will not 
"break," because the supply will be discharged 
through the overflow pipe. If the water supply is 
shut off, steam will appear, but as soon as the 
water supply is restored it will take it up and 
discharge it into the boilers, hence the name 
"automatic." 

The internal parts of an injector must bear a cer- 
tain relation to each other, or else it will not deliver 
water against pressure. This comparative size is 



AND THEORY. 113 

determined by the manufacturers, according to ser- 
vice for which the machine is designed, and it will 
operate indefinitely if these proportions are pre- 
served, but unfortunately this is not easily done, 
for the passage of water and steam at great velocity 
wears some of them larger, while the accumulation 
of scale reduces the size of others. As this is a 
slow process, the injector becomes less and less 
reliable, soon declines to start at the first trial, and 
finally refuses to force water into the boilers. 

This is always a source of perplexity to the engi- 
neer, especially if his experience is limited, because 
there are no moving parts that he can adjust or 
change, therefore he feels helpless. When an 
injector begins to fail in this way it should be dis- 
connected, filled with a solution consisting of 1 
part muriatic acid and 5 parts of water, allowed 
to stand about 12 hours, and then be thoroughly 
washed out. This will frequently make it almost 
as reliable as a new one. 

Failure to properly connect injectors is a prolific 
source of trouble and annoyance, for dry steam at 
full boiler pressure must be supplied, hence it w T ill 
not do to take steam from any pipe that happens to 
be convenient, without regard to other conditions. 

The best plan is to take it directly from the steam 
space of the boiler, but where this is not practical, 
a pipe that is of ample size for its required service 



114 ENGINEERING PRACTICE 

may be tapped on the side, or the top. Connec- 
tion should not be made into the bottom, because 
the steam will be wet on account of the condensa- 
tion in the big pipe, preventing the best results 
from being secured. 

Sometimes an injector will stop working, and 
steam will be blown into the tank from which the 
water is taken, so that it will be heated, and when 
the engineer tries to start the machine it will not 
respond because the water is too warm to condense 
the steam. 

The capacity of an injector is usually based on 
the amount of water it will deliver on a lift of 
about 2 feet, so that if it is used on a lift of 18 or 20 
feet it will not deliver its full capacity, and if the 
water is delivered to it under pressure, its rated 
capacity will be exceeded. Experiments made by 
the writer show that with a water pressure of 35 
pounds the capacity was increased more than 15 
per cent over what it was on a lift of less than 2 
feet. 

The ordinary injector will not deliver water 
against a pressure that is much higher than the 
steam pressure used to operate it, but it is possible 
to design one that will work against four times the 
steam pressure. This is done in the case of in- 
jectors used to test boilers with the hydrostatic test, 
and some engineers prefer them to test pumps, 



AND THEORY. 115 

because they deliver warm water for testing pur- 
poses. 

This brings us to a consideration of the theory 
of the injector, and the principles which cause it to 
operate. Some engineers claim that as the steam 
enters the combining tube its velocity is very great, 
and as at least a portion of this velocity is imparted 
to the water, its momentum carries it into the 
boiler. Others have claimed that inasmuch as the 
steam is immediately condensed its volume is greatly 
reduced, hence the total force of the steam jet is 
concentrated on a comparatively small area on the 
water, therefore the excess of pressure forces it into 
the boiler. 

Experiments that have been carefully conducted 
by reliable engineers, show conclusively that both 
of these principles combine to render the injector 
effective. As the jet enters the combining tube its 
velocity is very great, but it rapidly decreases as the 
tube expands. At the entrance of this tube the 
pressure is low, but it increases rapidly as the tube is 
traversed until its maximum is reached at the large 
end of it, and the water is forced into the boiler. 

Injectors that are commonly used for boiler feed- 
ing will not work against a pressure much higher 
than that on the boiler which supplies them with 
steam, because if designed to do this it would 
result in a waste of fuel on ordinary work, for the 



Il6 ENGINEERING PRACTICE 

idea that all of the heat in the steam taken from a 
boiler to run an injector is returned in the feed 
water, regardless of conditions, is not correct, be- 
cause some of it must disappear in doing work, and 
this cannot be reclaimed. Furthermore, one that 
is properly proportioned for the service required is 
the most economical, and not one that is intended 
to work against four times the boiler pressure. 

It has been demonstrated by experiments that 
steam at 25 pounds absolute pressure flows into the 
atmosphere at the rate of 864 feet per second, and 
as the pressure is raised the velocity increases slow- 
ly, until at a 100 pounds it is 900 feet per second, 
therefore the statement that the velocity of steam 
at ordinary working pressures is 900 feet per second 
is approximately true. 

The velocity of steam at any pressure may be 
calculated by the following rule, which is based 
upon the experiments above mentioned : 

Multiply the square root of the height in feet, of 
a column of steam one inch square, of uniform den- 
sity, the weight of which is equal to the absolute 
pressure per square inch on the boiler, by 3 .6 The 
product is the velocity in feet per second. 

The height of this column may be determined by 
dividing the absolute pressure by the weight of one 
cubic foot of steam at the given pressure, and mul- 
tiplying the quotient by 144. 



AND THEORY. 117 

For example, suppose that the pressure is 60 
pounds by the gage, or 75 pounds absolute, the 
weight of which is .1759 pound per cubic foot. 
The height of the column of steam is found as fol- 
lows: 75-^.1759x144 = 61,397 the square root of 
which is 247.8. Then 247.8x3.6 = 892 feet per 
second. 

When this steam is discharged into the atmos- 
phere it immediately begins to expand at a ratio of 
1.624 therefore the velocity of the expanded steam 
at 75 pounds absolute pressure is 892 x 1.624 = 1,448 
feet per second. 

When making calculations to determine the 
weight of steam that will be discharged through an 
orifice of given size, under a stated pressure, the 
velocity and the weight at the given pressure 
should be taken, for if the velocity of the expanded 
steam is used, it should be remembered that the 
pressure is reduced to that of the atmosphere, and 
the weight at atmospheric pressure must be used 
in the calculation. 

Due consideration of the above shows that the 
velocity of steam, as it enters an injector, is very 
great, so that under ideal conditions it should handle 
a very large quantity of water compared with the 
weight of steam used, but in practice this is reduced 
to about 15 times the weight of steam on a lift of 
2 feet, and to about 7 when the lift is increased 



nS 



ENGINEERING PRACTICE 



to 20 feet. This reduction is due to decreased 
velocity of steam as friction reduces it to .6 of the 
above calculated speed under fair conditions, also 
to the presence of water in the steam, and other 
unavoidable conditions. 

A leak in the suction pipe of an injector may not 
prevent it from lifting the water and discharging 
it at the overflow valve, but when an attempt is 
made to force it into the boilers, the jet may 
u break," so that the steam will be forced down 
the suction pipe. If a foot valve is put on the 
lower end of this pipe, the leak may be located by 
the escaping steam. With a perfectly tight suc- 
tion pipe, the foot valve should be omitted. 




DUPLEX HANCOCK IXSPIRATOR, 



AND THEORY. 119 



CHAPTER 18. 



STEAM PIPE COVERING. 

The object of covering a steam pipe with some 
non-conducting material is to prevent the escape of 
heat, and reduce the condensation of steam and 
accumulation of water in the pipe as much as pos- 
sible. In order to appreciate the value of a good 
pipe covering we must understand something about 
the amount of steam that will be condensed in an 
unprotected pipe, and while carefully conducted 
experiments give somewhat different results, still 
we may learn much from them. 

Taking the average of four that are reported by 
the same number of very good authorities, we find 
that one, four hundred and twentieth part of a 
pound of steam was condensed for each square foot 
of surface per hour, for each degree difference of 
temperature, hence the rule to determine the 
amount of steam condensed per hour: 

Multiply the number of square feet exposed to the 
air, by the difference between the temperature of 



120 ENGINEERING PRACTICE 

the air and steam, and divide the product by 420. 
The quotient will be the number of pounds con- 
densed. 

For example, suppose that we have 150 feet of 6 
inch pipe, carrying 75 pounds pressure, in air 
whose temperature is 50 Fah. How much steam 
will be condensed per hour ? We will assume that 
the external diameter of the pipe is 6.5 inches 
when its circumference will be 6.5 x 3.14^ = 20.4 
inches, and for each foot in length there will be 
20.4x12 = 244.8 square inches, or 1.7 square feet. 
The pipe being 150 feet long, 1.7 x 150=255 square 
feet exposed to the air. The temperature of steam 
at 75 + 15 = 90 pounds absolute pressure is 320 
and the difference between that and the air is 320 
— 50=270° Then 255 x 270-^-420=164 pounds of 
steam condensed per hour. 

If the boilers evaporate 8 pounds of water per 
pound of coal burned, there are 164 -=- 8 =20.5 
pounds of coal lost per hour, or 205 pounds per 
day of 10 hours. Under some circumstances, how- 
ever, the condensation will be going on for 24 hours 
per day, making 492 pounds. 

The engineer should not make the mistake of 
saying that a pipe covering will save all of this, 
for it will not, as some will be condensed even then, 
but a good covering will reduce the condensation 
to about one-third of the above. A dead air space 



AND THEORY. 121 

between the pipe and covering proves a very good 
non-conductor of heat, but the outer part of it 
must not be porous, for if it is air will circulate and 
the covering prove less efficient accordingly. 

The number of heat units lost by condensation 
may be determined by adding the sensible and the 
latent heat of the steam together, and subtracting 
the temperature of the condensed steam. In or- 
dinary practice, where the water passes off with 
the steam, this amounts to the same as simply tak- 
ing the latent heat of the steam. 

The latent heat of steam, of 90 pounds pressure, 
is 889 heat units, and its sensible heat is 320 or 
1,209 total. (Some tables give it as 1,211). The 
temperature of the water remaining in the pipe 
with the steam is the same as the steam. Then 
1,209 — 320 = 889 heat units lost for each pound 
of steam condensed. 

Furthermore, as this water at 320 is sometimes 
not used for any good purpose, still more heat is lost, 
which may be calculated by subtracting the tem- 
perature of the water as it enters the boiler from 
the temperature as above stated. If it leaves the 
heater and enters the boiler at 210 then 320 — 210 
= no° more for each pound, or no heat units. 

This is assuming that the water is heated by ex- 
haust steam, or by a flue heater where heat is util- 
ized that would otherwise be wasted. Then 889 + 



122 ENGINEERING PRACTICE. 

no =999 heat units lost for each pound, and as 
we have 164 pounds per hour 999 x 164 = 163,836 
per hour or 2,730 per minute. If we base the 
calculation on the temperature of the water 
as it enters the heater, the loss will be greater 
still. 

Now a heat unit is stated to be equivalent to 
772 foot pounds by some authorities, and 779 by 
others, but taking the former as correct we have 
2,730x772=2,107,560 foot pounds. As 33,000 
foot pounds per minute constitute a horse power, 
we may determine the horse power lost by dividing 
this by the number and 2,107,560 -s- 33,000 = 63.8 
horse power. 

It is not correct to say that this might be saved 
by using pipe covering for a large portion of 
it will be lost under the best conditions found. If 
we assume that but ten per cent, of the value of the 
steam is utilized in the engine, then 63. 8x .10 = 
6.38 horse power lost at the engine, on account of 
condensation in the pipe. 

The result of experiments made to determine 
this point is, that a pipe covering 1 inch thickwill 
give good results, if made of the best materials, 
but for general practice this should be increased to 
1 1 inches. A style of covering that can be removed 
and replaced at pleasure is very convenient when 
repairs are to be made, but some of them burn and 



AND THEORY. 123 

char so easily that when they are once removed 
they cannot be put back again. 

The saving made by using a good pipe covering 
is sometimes much greater than is accounted for by 
the above calculation, for if the condensed steam or 
hot water collects in one part of the main steam 
pipe of an engine, on account of the pipe being 
highest near the engine, it may be thrown forward 
in a body, causing a cylinder head to be blown off. 
If a separator is attached to the pipe, the water of 
condensation may be returned to the boilers by 
means of a steam loop, which is an arrangement of 
piping whereby the weight of a column of water 
will cause it to be discharged into the boiler by 
force of gravity, the steam pressure being equalized. 
If a trap that discharges into the sewer is used to 
take the water of condensation out of a heating 
system, the drip from the separator may be attached 
to the receiver of the trap. 



LABOR. 



When an engineer has no special interest in his 
plant, or his work, then the employment that 
should be an agreeable occupation, becomes hard 
labor. 



124 



ENGINEERING PRACTICE 




THE BRAINERD STEAM TRAP, 



STEAM APPLIANCES. 
Steam users sometimes think that appliances 
such as steam traps, damper regulators, high and 
low water detectors, feed water heaters, injectors 
for use when exhaust steam is not available for 
heating the feed water, sight feed lubricators, and 
indicators are not worth as much as they cost, but 
this is a mistake, for the most successful plants are 
equipped with those above mentioned, also others, 
and it is difficult to effectively argue against any- 
thing that is successful. A plant can be run with- 
out them, but that does not prove that it is 
economical or wise to do so. 



AND THEORY, 1 25 



CHAPTER 19, 



STEAM HEATING APPARATUS. 

Where a building is piped for steam heating by 
direct radiation, and one or more engines are used 
for power purposes, the exhaust steam from the 
engines, and also from the pumps, should discharge 
into the heating system. It should all pass into a 
separator, however, in order that the cylinder oil 
may be extracted, because it is not needed on the 
inside of the pipes, neither is it wanted in the boil- 
ers. A good separator will so effectually remove 
it that scarcely any traces of it will remain, pro- 
vided the drip from the separator is constantly 
open. It is the custom of some firemen and jani- 
tors to close this drip for the greater portion of the 
time, opening it occasionally to allow the water and 
oil to run to the sewer. This is a great mistake, 
for the body of the separator will soon fill with 
water, then the oil will pass over into the system. 

There is, or should be, a glass gage on every sep- 
arator, and if there is never any water in this glass 



126 ENGINEERING PRACTICE 

it is a good sign that there is none in the separa- 
tor. The drip valve need not be always wide open, 
as that would cause a loss of steam, but it should 
be left partly open, and occasionally opened wide 
for an hour or more, in order that the accumulated 
grease may be blown out. 

Probably the exhaust steam will not be enough 
to heat the building, in which case live steam must 
be used to make up the deficiency. x\s the amount 
of steam needed will vary with the weather, and 
as the amount furnished by the engines and pumps 
will change with the load on them, the amount 
needed directly from the boilers will vary constantly, 
so that some means must be provided for furnish- 
ing this automatically, or it will require constant 
attention from the engineer. 

To avoid this a reducing valve must be provided 
which will reduce the boiler pressure to from 2 to 
10 pounds, according to what is required. The 
pressure in the heating system represents the back 
pressure on the engine, above the atmosphere, and 
there is a constant controversy among engineers as 
to w T hether it pays to use this steam or not. It 
appears to be a very simple matter that should be 
easily settled. 

If an engine is exhausting into the atmosphere 
direct, and we add 5 pounds to the back pressure, 
the governor immediately adds 5 pounds to the 



AND THEORY. I2J 

forward pressure, and the loss in power may be 
calculated by multiplying the horse power constant 
at the given speed, by the increase in the back 
pressure. If the piston is 20 inches in diameter 
and travels 480 feet per minute, then 20x20 x .7854 
X480 -T- 33,000 = 4.567 which is the horse power 
constant. (See Chapter 9). If the back pressure 
is 5 pounds, then 4.567x5 = 22.835 horse power 
lost. 

When the engine exhausts into a heating system 
the case is different, for nothing is lost except what 
disappears in the act of doing work, provided there 
is radiating surface sufficient to condense all of the 
steam. 

If the engine was already working up to its full 
capacity, it might not be expedient to add five or 
ten pounds back pressure, as it would cause the 
speed to be reduced, but such cases are seldom 
found in practice. Judging from the way this 
question is frequently discussed, it might be sup- 
posed that all of the steam required to overcome 
the added backpressure, is lost, but this is far from 
true. 

The power actually used in passing steam through 
an automatic engine, on its way to a heating sys- 
tem, may be computed by the following rule : 

Multiply the weight of steam used per minute by 
its total heat, minus the total heat at release pres- 



128 ENGINEERING PRACTICE. 

sure, and the product will be the heat units lost. 
Multiply this by 772, because one heat unit is equal 
to 772 foot pounds, and the product will be the 
number of foot pounds. Divide by 33,000 and the 
quotient will be the horse power. 

The weight of steam may be determined as fol- 
lows : 

Multiply the area of the cylinder in square inches, 
by the distance in inches traveled by the piston 
when the cut-off takes place, and divide by 1,728. 
Multiply by the number of strokes per minute, and 
by the weight of one cubic foot at given pressure. 
The product will be the number of pounds used 
per minute. 

For illustration, take an engine 20 by 48 inches, 
at 60 revolutions per minute, using steam at 105 
pounds initial pressure and releasing it at 21 pounds 
pressure, both of which are absolute. The ratio 
of expansion would be 105 -f- 21 =5 or in other 
words the cut off would take place at one-fifth 
stroke, and 48 -=-5 = 9.6 inches. Area of cylinder 
is 314 square inches and 314x9.6 = 3,014 cubic 
inches or 1.744 cubic feet. There are 120 strokes 
per minute, and the steam weighs .2414 pounds per 
cubic foot. Then 1.744 x 120 x .2414=50.52 
pounds used per minute, the total heat of which is 
1,214 heat units. This steam is expanded to 21 
pounds pressure, the total heat of which is 1,183 



AND THEORY. 129 

above zero. In some cases it is necessary to take 
the heat units above 32, but in this case it makes 
ho difference in the result whether one or the other 
is taken, provided the same is used for both initial 
and release pressures. 1,214 — 1,183 = 31 heat 
units difference for each pound, and as 50.52 pounds 
are used per minute, the total is 50.52 x 31 = 
1,566.12 heat units used. 1,566.12x772-1-33,000 
= 36.64 horse power. 

This is a theoretical calculation, in which all of 
the conditions are assumed to be perfect, and the 
effects of condensation and re-evaporation are not 
taken into account. It also differs from a calcula- 
tion made to determine the number of heat units 
used where an engine is exhausting into the atmos- 
phere. 

This engine, under given conditions, assuming 
the back pressure to be 15 pounds above a vacuum, 
will develop 181. 7 horse power, 20 per cent of the 
heat being used and 80 per cent going to the heat- 
ing system. 

In the case of a throttling engine, where the 
terminal pressure is nearly or quite equal to the 
initial pressure, the heat units used, or absorbed, 
may be calculated as follows : 

Determine the number of foot pounds developed 
in one minute, and divide by 772. The quotient 
will be the units used. 



130 ENGINEERING PRACTICE 

If the area of a piston is 201 square inches, the 
stroke 3 feet, the speed 80 revolutions per minute, 
and the mean effective pressure 45 pounds, then 
201 x3x2x8ox45-r 772 = 5,624 heat units used per 
minute. 

The number of heat units passing to the heating 
system in this case is found as follows : The cylin- 
der contains 4.1875 cubic feet, and it is filled 160 
times per minute, making 670 cubic feet at .1425 
pound per cubic foot. Then 670 x .1425 =95.475 
pounds per minute. This steam contains 1,170 
heat units above 32 Fah., therefore 95.475x1,170 
= 111,705 heat units per minute. 

When we add the tw r o quantities together we find 
that 117,329 heat units are accounted for, and that 
95.2 per cent of them pass to the heating system 
while 4.8 per cent are lost, or disappear in doing 
work. If this engine exhausted directly into the 
atmosphere 4.8 per cent would be utilized, and 
95.2 per cent lost. 

The indirect system of steam heating, including 
a large fan for forcing the heated air where it is 
wanted in the several rooms of a building, is very 
popular at the present time, and justly so, on 
account of its efficiency and convenience. 

As the air is forced into the building, it not only 
heats it rapidly, but also provides for necessary 
ventilation, which is an important point in its favor. 



AND THEORY. 131 

Calculations made to determine the amount of 
steam condensed per hour in a steam pipe, or in a 
radiator, under conditions relating to the direct 
system of heating, will not answer for use in con- 
nection with the forced blast system, because the 
condensation is much more rapid when the air cir- 
culates so much faster. 

The amount of steam condensed in the direct sys- 
tem may be multiplied by a factor for the forced 
blast system, but this factor cannot be stated arbi- 
trarily because it will vary with all changes in 
speed of the fan. The only practical way to deter- 
mine it is by experiment in each particular case. 

Where the speed of fan is slow this factor will be 
about 2, but when run at a fast speed it may be 
increased to 5. 

The steam used to operate one of these fans is 
not all lost, because the exhaust steam is used in 
the tempering coil, which is a coil used to heat the 
air slightly before it goes to the regular heating 
coils. 



A QUERY. 
Some engineers are qualified for better positions 
than they now hold, while others are not compe- 
tent for their present situations, hence find it diffi- 
cult to hold them. Which condition is the most 
desirable ? 



rx2 



ENGINEERING PRACTICE 




A DIRECT CCNNECTED FAN. 

An apparatus for forcing hot air into a building 
for heating and ventilating purposes, driven by a 
double horizontal engine, either side of which may 
be disconnected and the fan run by one side only. 

o 

THE SAFE SIDE. 

When an engineer leaves his situation on account 
of unsatisfactory treatment, and his successor has 
trouble with some of the machinery, the retiring 
engineer is usually blamed for neglecting his duties, 
or for malicious conduct. In order to prevent this 
unpleasant state of affairs he should assist the new 
man at least one day, and then leave him to operate 
the plant according to his own judgment. This is 
honorable, and should be satisfactory to all con- 
cerned. 



AND THEORY. 133 



CHAPTER 20 



REDUCING VALVES, TRAPS AND RECEIVERS. 

Inasmuch as passing steam through an engine 
on its way to a heating plant results in the produc- 
tion of power, it has been assumed by some that 
when a reducing valve is used to reduce the pres- 
sure for heating, it absorbs the power in some mys- 
terious way, and consequently causes a great loss. 
This is a mistake, for the conditions are very dif- 
ferent from those found when an engine is the re- 
ducing medium. 

Take the case used for illustration in the preced- 
ing chapter, where steam at 105 pounds absolute is 
reduced to 21 pounds, but using a reducing valve 
instead of an engine, we find that while the steam, 
before it enters the valve, has a temperature of 
331 Fah., the temperature corresponding to the 
pressure after it leaves the valve is 228 , but it 
really possesses a much higher temperature, which 
is explained as follows: 



134 ENGINEERING PRACTICE 

When the steam at 331° passes through the valve, 
it does not leave this heat behind it, but it passes 
through with the steam, although the pressure is 
reduced, and this heat raises the temperature of the 
low pressure steam, or in other words it super- 
heats it. 

The difference in temperature is 103° if we take 
the pressure as a basis, but the lew pressure steam 
contains more heat than this accounts for, which 
is due to the low specific heat of steam. 

The specific heat of any body, liquid or gas, is 
the amount of heat required to raise the tempera- 
ture of one pound of it one degree, when compared 
with the heat needed to raise the temperature of 
one pound of water from 39° to 40" Fah., as stated 
by some authorities, while others take it from 32 D 
to 33 . The difference is practically of no account, 
but inasmuch as water reaches its maximum den- 
sity at 39^ it is well to use that as a standard. 

The specific heat of steam is about one-half that 
of water, or, to be exact, it is .475 hence, when 
we wish to determine the temperature due to super- 
heating, we must divide the difference in tempera- 
tures corresponding to the pressures by .475 In 
this case it is 103 and 103 -r .475 = 2i6 : . Then 
228 + 216= 444° temperature of the low pressure 
steam. The whole of this will probably not be 
realized in practice, for some of it will be lost by 



AND THEORY. 135 

radiation, and if there is any water in the steam 
after it passes through the reducing valve, the 
extra heat passing over will be partially or wholly 
absorbed in evaporating this water, so that it is not 
lost, although the thermometer may not indicate 
all of it. 

After steam has passed the engine or the reduc- 
ing valve, it is conveyed to the radiators, or coils 
of pipe located in the building to be heated, where 
it is condensed, during which process the latent 
heat of it is given out and is utilized in heating 
the rooms. The water naturally seeks the lowest 
point in the system, and if the pipes are not prop- 
erly pitched, so that the drainage is perfect, water 
will stand in the low places, and pounding and 
thumping will be the result. 

The plan of using an open tank to receive the 
water, is seldom adopted at the present time, be- 
cause it allows so much heat to escape to the at- 
mosphere. A closed receiver is usually provided 
for this purpose, and the water in it may be put 
back into the boilers by means of a return trap 
located above the water line of the boilers. A 
mixture of water and steam passes from the re- 
ceiver to the trap, where the water settles in the 
bowl of the trap, and its weight causes a valve 
called an equalizing valve to be opened, admitting 
live steam to the space above the water. This 



136 ENGINEERING PRACTICE 

equalizes the pressure, when the weight of water 
causes it to flow to the boilers. 

Another very good plan for returning this water 
is to provide a large cast iron receiver at the lowest 
point in the system, and in this receiver there is a 
hollow copper float which rises and falls with the 
water level. By means of suitable levers and a 
small shaft, this float is connected to the throttle 
valve of a duplex pump, located on the same base 
with the receiver, and when this float rises the 
throttle valve is opened and the pump starts up. 
When the water is pumped out, the float falls and 
the throttle valve is closed. 

The amount of steam that will be condensed un- 
der given conditions was illustrated and explained 
in Chapter 18, and this rule applies to heating sys- 
tems where forced ventilation is not used. 

Suppose that we have 5,000 feet of ii inch 
pipe, filled with steam at 5 pounds gage pressure, 
the temperature of the room being 6o° Fah. How 
much steam will be condensed per hour ? If the 
outside diameter of a ij inch pipe is if or 1.62 
inches, its circumference will be 5.09 inches. 
5.09 x 12 -f- 144 = .424 square feet per foot in 
length. As there are 5,000 feet, then 5,000 x 
.424 = 2,120 square feet. The difference in tem- 
perature is 228 — 60 = 168 and 2,120 x 168 -f- 420 
= 848 pounds per hour. 



AND THEORY. 1 37 

When a trap is used to return the water to the 
boilers, it is a good plan to put a tee in the pipe 
between the trap and its receiver, for the following 
reason. When steam is first admitted to a heating 
system on a cold morning, the return water is cold 
and there is some air mixed with it. If this goes to 
the trap it frequently causes pounding in the pipes 
which is both unpleasant and dangerous. Where this 
occurs a nipple may be put into this tee followed by 
a valve which may be opened to allow the water to 
escape to the sewer, or to a tank provided for the 
purpose, if it is desired to save it. When the re- 
turning water is warm this valve may be closed, 
and the trap will put the water into the boilers 
without trouble. 

When a duplex pump is used to return the water 
of condensation, it will pump this water without 
trouble, but some provision should be made for 
heating it, as pumping cold water into hot 
boilers causes uneven contraction of the plates, 
bringing more stress upon them than would ever 
be caused by any ordinary steam pressure. 

An outlet should be provided between the pump 
and the check valves near the boilers, so that the 
water may be allowed to go to the sewer, for this 
will be badly needed when the system is new, or 
when additions have been made to it, for iron chips, 
red lead and other undesirable matter is sure to be 



i33 



ENGINEERING PRACTICE 



found on the inside of new pipe, and it is not want- 
ed in the boilers, but should be sent into the sewer. 

I have seen a pump partially disabled by leaky 
valves, yet it discharged it into the sewer until 
there was a chance to make repairs, thus allowing 
the building in which it was located to be occupied 
without interruption, w T hich could not have been 
done had this outlet been omitted. 

In concluding this work the author would say to 
the steam maker, study the theoretical, as well as 
the practical part of your business, and to the 
steam user, when you secure an engineer that is 
competent, and works for your interests, show ap- 
preciation of his services. 




PUMP AND RECEIVER. 



AND THEORY. 



139 




QUADRUPLE SIGHT FEED LUBRICATOR. 

This lubricator has four separate sight feeds, and 
by a very ingenious arrangement of the internal 
parts it is possible to lubricate the cylinders of a 
quadruple expansion, or a four cylinder triple 
expansion engine from it, although the pressures 
may range from the lowest to the highest required. 



140 



ENGINEERING PRACTICE 



o 

o o Jl . 

o Q ^fP 55 

O I 




Left Hand Engine: 



AND THEORY. 



I 4 I 




Right Hand Engine: 



T42 



ENGINEERING PRACTICE 



i.i I r tffrrir 



(Pfejf 1 • ' Wt 




A VERTICAL CROSS COMPOUND ENGINE, DIRECT 
CONNECTED TO LINE OF MILL SHAFTING. 



APPENDIX. 143 



APPENDIX. 



POUNDING IN STEAM ENGINES. 

Sometimes it is more difficult for the physician to 
properly locate the name and nature of the disease 
from which his patient is suffering, than it is for 
him to apply efficient remedies after it is located, 
and frequently it is more difficult for the steam en- 
gineer to locate the cause of a pound in his engine, 
than it is for him to stop it, after its true cause is 
discovered. 

When the engineer in charge of a steam plant, 
having every opportunity to examine each part of 
the same, and profit by suggestions of his assistants 
and friends, finds it difficult to locate the cause of 
a pound in his engine, it is plainly much more diffi- 
cult for an engineer living at a distance to do so, as 
all of his information is from letters, instead of be- 
ing able to profit by a personal inspection of the 
machine. 

It is, however, frequently very beneficial to relate 
the experience of others along this line, as this 



144 APPENDIX. 

serves to remind the engineer in trouble of possible 
ways out of it. For this purpose the following 
ideas, suggestions, and practical points are offered, 
as they are sure to prove valuable. 

i. In one case an engine was pounding badly, 
and after trying in vain to locate the cause, the 
engineer sent for the engine builder and referred 
the case to him. After a long search, in which 
both of them took an active part, it was discovered 
that the key in the fly wheel was loose, and a few 
blows with a hammer stopped the pounding. As 
the noise caused by this loose part would telephone 
along the crank shaft, crank, connecting rod and 
piston, it made the location of its cause quite diffi- 
cult. 

2. I once had charge of an engine on which the 
eccentric was not round, and the only way to keep 
it quiet was to use heavy grease on it instead of oil. 
When the engine was stopped in proper position, 
the eccentric straps were loose, so that they could 
be shaken by hand. It was possible to adjust them 
so that they would be tight enough to prevent 
noise, but when this was done and the eccentric 
rod disconnected from the rock shaft, and the end 
of it raised, the straps soon bound on the eccentric, 
thus showing that if the engine had been started 
up without this test, some part of it would have 
been broken. 



APPENDIX. 145 

3. If there is lost motion in the main bearing it 
may cause a pound. As this is so apparent, it may 
be considered unworthy of mention by some, but 
nevertheless there are cases in which it is not so 
easily discovered as might be expected. Where 
the engine is fitted with a valve gear that may be 
worked by hand, the crank should be placed on a 
center, and while an assistant admits steam to al- 
ternate ends of the cylinder, the engineer may 
detect the lost motion by feeling of the shaft and 
box. In other cases it may be discovered by run- 
ning the engine slowly, with as heavy a load as can 
be utilized. If the engine is new, and the shaft 
perfectly round, the quarter boxes may be set up to 
the shaft snugly, and then slackened until the shaft 
can revolve freely, but if the engine has been in 
use a long time it is quite possible that the shaft 
maybe worn flat, so that it will be impossible to 
stop the pounding without making the shaft round, 
and rebabbiting the quarter boxes. 

4. Sometimes the crank will become loose on the 
shaft and thus cause a pound. 

5. When crank pins are put in place they are 
supposed to remain there until taken out, but they 
do not always do so, for sometimes they work loose 
and cause a pound. When this defect is discov- 
ered it is well to expand the end of pin in the crank 
by means of a peen hammer, as a measure of tern- 



146 APPENDIX. 

poiary security, but the only way to secure a per- 
manent job is to make a new pin, bore out the hole 
in the crank , and force the pin into place. 

6. Lost motion in crank pin boxes quite fre- 
quently causes pounding, and sometimes this is the 
case when the key is driven down as far as it will 
go, because the boxes come together at top andbot- 
tom before they make a proper fit on the pin. For 
the larger portion of stationary work it is better to 
take one of the boxes out and plane it off, so that 
the same trouble will not appear again in the near 
future, although in some cases it may be necessary 
to file the boxes until they will come together and 
still fit nicely on the pin. If a crank pin heats it 
is not proof that there is no lost motion in the 
boxes, as it is quite possible for it to heat on ac- 
count of the pounding. 

7. Sometimes a noise is caused by lost motion 
endwise on the pin, because the boxes are not wide 
enough to fill the space between face of crank and 
head of the pin. In one case I succeeded in stop- 
ping a pound of this kind by cutting a washer out 
of sheet bi;ass, separating it at one side and spring- 
ing it over the pin. It filled the space next to the 
crank and lasted for a long time. 

8. The above suggestions apply equally well to 
the wrist pin, for although it is supported at both 



APPENDIX. 147 

ends, still it sometimes works loose in the cross- 
head and causes a pound. 

9. The cross-head may be responsible for a 
pound, where it does not travel over the ends of the 
guides, for many years of service may leave small 
shoulders at the end of its travel, and when some 
adjustment of the crank or wrist pin boxes is made, 
it may cause the cross-head to strike one of these 
shoulders and make trouble. 

10. It is sometimes said that where an engine 
runs "over," or in other words when the top of 
the fly wheel travels from the cylinder, the pres- 
sure of the cross-head is downward on the guides 
throughout the whole stroke, but this is not always 
true, for when the effects of compression in the cyl- 
inder are felt, it causes the cross-head to be lifted, 
and when it comes down it causes a pound. This 
can be easily demonstrated on the engine I have 
charge of at the present time. 

11. When an engine of the Corliss type runs 
Cl under," or, in other words, when the top of the 
fly wheel travels toward the cylinder, the effect 
of steam operating on the piston is to lift the cross- 
head and, as a rule, this will make an annoying 
pound, unless adjustments are very nicely made. 
It is not always practical to so make these adjust- 
ments, as I once found in the case of a new engine 
of this kind in a silk mill, for when the engine was 



148 APPENDIX. 

cold the distance between the guides was the same 
at both ends of the stroke, but when well warmed 
up in service it was greater at the cylinder end, 
hence the crosshead would lift at every revolution. 

12. Many of the crossheads now in use are sup- 
ported by a single stud of proper size, which sets 
into the lower " shoe " like the end of a vertical 
shaft into a step. After many years of service they 
become worn, so that there is lost motion between 
the two parts, and this makes its presence known 
by heavy pounds at both ends of the stroke. Some- 
times a hole is drilled from the end of the u shoe M 
to the stud, and a long set screw put in to stop the 
noise, but while this may answer the purpose for a 
time, still the proper way is to turn the stud down 
in a lathe, bore out the hole, and bush it to fit the 
stud. 

13. Sometimes when a piston rod is fastened into 
a crosshead by means of a key, said key becomes 
worn in the center, and when steam acts on the 
crank end of the cylinder, the rod is pulled out as 
far as the key will allow it to come, and when 
steam acts on the other end, the rod is forced 
in as far as the shoulder on it will admit of, and the 
result is a pound that can be heard all through the 
engine room. It may be impossible to drive the 
key any farther, hence the engineer will conclude 
that the trouble is elsewhere. 



APPENDIX. 149 

14. In one case that I knew of, where the piston 
rod screwed into the crosshead, there was a bad 
pound, but it was not heard continuously. It would 
appear for a short time, and then disappear with- 
out apparent cause. Investigation showed that the 
jam nut was loose, and when the piston rod un- 
screwed for perhaps quarter of a turn, the pound 
would appear, and when it screwed up again it dis- 
appeared. The remedy was easily applied, but it 
was a narrow escape from serious accident. 

15. Sometimes when the packing in a piston rod 
stuffing box becomes hard and stiff from long use, 
and on account of the gland being screwed down too 
tight, it will cause a pound, but to this rule there 
are some exceptions. 

16. All modern engines have counterbores, the 
object of which is to prevent shoulders being left 
at each end of the cylinder as it becomes worn from 
long service, but in many of them this object is not 
realized on account of a miscalculation somewhere, 
the result being that the packing rings do not 
travel to the counterbore as was intended, and 
shoulders are left where none are needed. When 
lost motion in the main bearing, the crank pin or 
the wrist pin boxes is taken up, it may change the 
position of piston when the engine is on either cen- 
ter. When in motion the rings strike one of the 
shoulders and a pound is the consequence. 



150 APPENDIX. 

17. I never knew of but one case in which a ring 
traveled wholly over into the counterbore, and it 
made a bad pound during the process. 

18. It is well for the rings to travel flush with 
the counterbore, but they should not go much 
beyond this point. If the counterbore is too deep, 
and half of the ring travels over the edge of it, the 
steam is given a chance to act on the surface so 
exposed, and may cause the ring to collapse, mak- 
ing a well defined pound. The remedy is to bore 
small holes through the piston and the follower 
plate, to admit steam to the under side of these 
rings, thus causing them to be balanced. This is 
frequently resorted to in cases where the Dunbar 
or similar rings are in use. The objection to it is 
that it causes the cylinder to wear larger at the 
ends than it does in the middle. 

19. If the piston has been in service for many 
years, the rings may be worn so that they are a 
loose fit in their places, and when their motion is 
reversed they are thrown from one side of the 
grooves in which they work, to the other, hence 
the noise. 

20. On the other hand, if the piston has been 
repaired, it is possible that the rings are clamped 
between the spider and the bull ring on one side, 
and the bull ring and the follower plate on the 
other, so that they cannot expand and contract to 



APPENDIX. 151 

follow the bore of the cylinder. In either of the 
two preceding cases the piston should be taken out 
and all of its parts put together while on the bench, 
so that the exact state of affairs may be known. 

21. When making repairs it sometimes happens 
that the bull ring and the packing rings are not 
replaced in the same position from which they 
were taken, but are turned in the cylinder, or they 
may be moved intentionally by the engineer, the 
result being a pound that it is difficult to account for, 
especially as it may appear to be in the crank pin 
boxes, or at some other point between the two 
extremes. The remedy is to replace the rings in 
their original positions, and in a large majority of 
cases it is better to let them remain in one position 
indefinitely. 

22. Sometimes a follower bolt will become loos- 
ened and strike the cylinder head, thus making a 
sharp pound. 

23. A certain engine was pounding badly, and 
all efforts to find the cause were fruitless until the 
piston was taken out and the rod placed in a ver- 
tical position with the piston on top, when the 
piston was found to be loose on the rod. It 
was thoroughly riveted in place and the trouble 
disappeared. 

24. In another case the low pressure piston of a 
tandem compound engine became loose, and after 



152 APPENDIX. 

the cause of the trouble was located it was an easy 
matter to tighten up the nut which was intended 
to hold it firmly in place, but the difficulty was in 
locating the disturbance. 

25. It was necessary to put a bushing in the low 
pressure cylinder of another compound engine, but 
it was made a trifle shorter than the cylinder, and 
becoming loose, moved endwise, making a pound 
that was exceedingly difficult to locate. 

26. The piston of another engine was taken out 
for inspection, cleaned and replaced, but the engi- 
neer did not center it accurately, hence when it 
reached the crank end of cylinder it did not move 
freely, the consequence being that a bad pound 
developed where there was none before. 

27. Some engines are so designed that steam is 
admitted to the cylinder through ports located on 
the under side of it, so that if the follower plate 
projects over the port when the engine is on the 
inside center, the steam being admitted very rap- 
idly and at very nearly boiler pressure, strikes the 
plate, and if the bull ring is not a close fit in the 
cylinder, it may be lifted up and cause a heavy 
pound. It is possible for this to take place where 
the ports are located on the side of cylinder, but 
not if they are on the top, as in Corliss engines. 

28. Slide valves are frequently designed to travel 
between two pairs of jam nuts on the valve rod, 



APPENDIX. 153 

and these are supposed to be adjusted so that there 
will be no lost motion and yet the valve will be free 
to travel on its seat, but unfortunately this is not 
always done, and if there is much lost motion here 
it will cause a pound if the steam pressure is high 
enough to cause much friction of the valve. 

29. With valves of the Corliss type, the stems 
are sliding fits in the valves when new, but as time 
advances they become worn, resulting in lost motion. 
As the pressure in the steam chest is high, and the 
valves are opened very rapidly, a pound is the con- 
sequence. 

30. Some of the vacuum dash pot plungers descend 
rapidly and with some force, so that if proper air 
cushions are not provided they cannot be expected 
to operate quietly. 

31. If the valves of an engine are not set so as 
to give a reasonable amount of compression, and 
also with sufficient lead to fill the cylinder with 
steam at nearly boiler pressure, it is only natural 
to expect a pronounced pound as each center is 
passed, although there are some exceptions to this 
rule. 

32. In a large majority of cases the pound in a 
engine is heard when the crank is on one or the 
other of the centers, and perhaps on each alter- 
nately, but in one case that I have good reasons for 
remembering, it put in an appearance when about 



154 APPENDIX. 

half of the stroke was completed. An application 
of the indicator showed that the exhaust valve on 
one end, closed at about half stroke, thus taking 
up lost motion in the crank pin and wrist pin boxes 
in the opposite direction, and, as a matter of course, 
making some noise about it. 

33. As usually made, the valve rod hook of an 
engine soon becomes worn where it bears on the 
stud in the wrist plate, and this makes a disagree- 
able noise. 

34. The lost motion in connections between the 
several parts of the valve gear of an engine, includ- 
ing the rockers, which are usually several feet dis- 
tant from the cylinder, will cause numerous pounds 
and knocks, and as the sounds are conduced to 
other parts of the engine, it adds to the difficulty 
of locating them. 

35. This list of causes was begun by mentioning 
one in a fly wheel, and it will be ended by calling 
attention to the fact that an unbalanced fly wheel 
on a high speed engine will cause pounding, and 
as none of the parts are loose or broken in such a 
case, it may cause a long search before the trouble 
is found. 

It is the sincere wish of the author that the fore- 
going suggestions may prove valuable to those 
whose duty it is to care for this class of machinery, 
and be appreciated accordingly. 



QUESTIONS. 155 



ENGINEERING PRACTICE AND THEORY. 



Answers to the following questions may be found 
in the chapters under which they appear in the list. 
The reader is advised to study the book carefully, 
then write out answers to the questions, and com- 
pare them with those found in the several chapters. 

Chapter i — Page 15. 

1. Why should an engineer thoroughly under 
stand his plant ? 

2. What is a practical engineer ? 

3. What is a theoretical engineer? 

4. Is a combination of the two desirable? 

5. What is steam? 

6. What is saturated steam ? 

7. What is wet steam? 

8. What is superheated steam ? 

9. What is gaseous steam ? 

10. How does water circulate in a boiler ? 

11. How long will the circulation continue? 

12. What is a heat unit ? 

13. At what temperature does water attain its 
greatest density ? 



I56 QUESTIONS. 

14. What is meant by the pressure of steam in 
pounds per square inch ? 

15. Could the steam pressure be determined by 
means of a column of water ? 

16. Does the height, or the diameter of a col- 
umn of water determine the pressure per square 
inch at the base of it ? 

17. What are molecules of water? 

18. What effect does heat have on these mole- 
cules ? 

19. Which is the more dense, steam of high or 
low pressure ? 

20. What is heat ? 

Chapter 2 — Page 20. 

21. How do you calculate the safe working pres- 
sure of a steam boiler ? 

22. How do you calculate the strength of a plate 
at the joint ? 

23. How do you calculate the strength of rivets 
at the joint ? 

24. If the strength of plates and rivets is not 
equal, which should be taken as a basis for the cal- 
culation ? 

25. Why are braces used in a boiler ? 

26. How do you determine the pitch of braces or 
stav bolts ? 



QUESTIONS. 157 

27. What is the difference between a brace and a 
stay bolt ? 

28. Why are stay bolts sometimes made hollow? 

29. When do they answer a double purpose ? 

30. What is the water leg of a boiler? 

31. What is a fusible plug? 

32. What should it be filled with? 

33. Where should it be located ? 

34. In what form should it be made ? 

35. How should it be cared for ? 



Chapter 3. — Page 26. 

36. Where should a safety valve be located ? 

37. Give a rule for locating the weight on a 
safety valve lever. 

38. What is the fulcrum ? 

39. Is it difficult to prove these rules ? 

40. Describe a way to prove safety valve rules ? 

41. How would you determine the weight nec- 
essay to put on a safety valve lever ? 

42. Give a rule for determining the pressure at 
which a safety valve will lift ? 

43. When designing a safety valve, how would 
you determine the length of the lever ? 

44. How large should a safety valve be for a 
given boiler ? 



158 QUESTIONS. 

45. Which is the most efficient for a given diam- 
eter, a pop or a lever valve ? 

46. How should safety valves be treated ? 

Chapter 4.— Page 31. 

47. What is meant by the heating surface of a 
boiler 9 

48. How can the amount of heating surface in a 
tubular boiler be calculated ? 

49. How many feet in length of a three inch tube 
makes a square foot of heating surface ? 

50. How can the amount of heating surface in a 
water tube boiler be determined ? 

51. What is the horse power of a boiler ? 

52. Can a rule be given for determining the horse 
power of a boiler by the heating surface it contains ? 

53. What is latent heat ? 

54. What is sensible heat ? 

55. What is the total heat of steam ? 

56. Explain a way to prove that latent heat 
exists. 

57. What are the objects sought in conducting 
boiler tests ? 

58. Explain the proper way to conduct a test ? 

Chapter 5. — Page 38. 

59. What is a calorimeter? 



QUESTIONS. 159 

60. How can a good sample of steam for testing 
be secured ? 

61. Explain one way to conduct a calorimeter 
test? 

62. How would you determine the pounds of 
water evaporated per pound of coal ? 

63. How may the weight of combustible used be 
determined ? 

64. How may we determine the weight of water 
evaporated per pound of combustible ? 

65. How may we determine the weight of water 
evaporated from and at 21 2° per pound of combusti- 
ble ? 

66. How are the efficiencies of boilers compared ? 

67. How may the actual performance of boilers 
be reduced to a standard for comparison ? 

68. How would you proceed to find the equiva- 
lent evaporation of a boiler ? 

69. How would you determine the per centage 
of moisture in coal ? 

Chapter 6. — Page 48. 

70. How many standards are there for deter- 
mining the power developed by a boiler ? 

71 • Can you explain both of them ? 
72. How much difference is there between the 
results obtained by them ? 



C 



l6o QUESTIONS. 

73. Explain the way to account for heat con- 
tained in water that passes off with the steam ? 

74. Is the horse power or a boiler a definite quan- 
tity ? 

75. Is it advisable to force boilers beyond their 
rated capacity ? 

76. What are the advantages and disadvantages 
of such a course ? 

yy. Should an engineer carry whatever pressure 
is necessary to do the work put upon his engine ? 

78. Is a live engineer better than a dead hero ? 

79. Should there be a penalty for carrying ex- 
cessive pressure on a boiler ? 

80. Should it apply to owner and engineer alike ? 

Chapter 7. — Page 54. 

81. What are the first duties of an engineer when 
coming into his engine and boiler rooms in the 
morning ? 

82. How would you proceed to start a simple > 
non-condensing engine ? 

83. How would you proceed to start a condens- 
ing engine? 

84. What is the effect of operating the valve gear 
by hand ? 

85. How would you proceed to start a compound 
condensing engine ? 



QUESTIONS. l6l 

86. Should the throttle valve be wide open while 
the engine is running ? 

87. Give the rule for determining the power of 
a double acting engine ? 

88. How do you calculate the piston speed for a 
single acting engine ? 

89. How do you calculate the power of a single 
acting engine with two cylinders ? 

90. How would you determine the mean effective 
prsssure of an engine while iu service ? 

91. Can you calculate the mean effective pressure 
of an engine without an indicator ? 

Chapter 8. — Page 59. 

92. What is a steam engine indicator? 

93. How does it resemble a recording steam gage? 

94. What must be considered in connection with 
the change of pressure during the stroke ? 

95. Explain how the indicator shows defects in 
valve setting ? 

96. How should it be attached to an engine ? 

97. Mention three forms of reducing motions ? 

98. How would you determine the mean effective 
pressure shown by a diagram, without a planime- 
ter? 

Chapter 9. — Page 64. 

99. What are planimeters used for ? 



162 QUESTIONS. 

ioo. How is the horse power of a double engine 
determined ? 

101. How is the horse power of a compound en- 
gine determined ? 

102. What is the object in building compound 
engines ? 

103. Why are they more economical than simple 
engines ? 

104. How do you find the horse power constant 
of a simple engine when the speed is given ? 

105. Is there another constant of this kind? 

106. How is it found and for what purpose is it 
used ? 

107. How do you determine the horse power con- 
stant of the low pressure cylinder of a compound 
engine ? 

108. Does this rule apply to triple and quadruple 
expansion engines ? 

Chapter 10. — Page 70. 

109. Give another rule for determining the power 
of a compound engine ? 

no. What change must be made here if the 
stroke of the high pressure is not equal to that of 
the low pressure side ? 

in. How would you determine the ratio of ex- 
pansion for each cylinder of a compound engine ? 



QUESTIONS. 163 

112. Give a rule for calculating the combined 
ratio of expansion? 

113. Give another rule for determining the com- 
bined ratio o*f expansion ? 

114. How can the actual combined ratio of expan- 
sion be determined from the indicator diagrams. 



Chapter ii. — Page 75. 

115. What is a receiver ? 

116. Why is it impractical to give a rule for 
determining the necessary size of receiver ? 

117. In general practice, how does the size of the 
high pressure cylinder of a compound engine, com- 
pare with the low pressure ? 

118. Is it always a good plan to convert a sim- 
ple engine into a compound ? 

119. Under what conditions will it be a paying 
investment ? 

120. What is a tandem compound engine ? 

121. What is a cross compound engine ? 

122. What are their advantages and disadvan- 
tages ? 

123. What is a u by-pass n on a compound en- 
gine ? 

124. What is a steeple compound engine ? 



164 questions. 

Chapter 12. — Page 80. 

125. How do you determine the power developed 
by a triple expansion engine ? 

126. What precautions should be taken when 
indicating these engines ? 

127. How may this be accomplished ? 

128. Can reliable results be obtained with one 
indicator ? 

129. How would you determine the actual com- 
bined ratio of expansion of a triple expansion 
engine, from the iudicator diagrams ? 

130. How would you calculate the total ratio of 
expansion for an engine of this type, without bring- 
ing all of the cylinders into the calculation ? 

131. What is the object inbuilding four cylinder 
triple expansion engines ? 

132. How would you determine the total ratio of 
expansion for a four cylinder, triple expansion 
engine ? 

Chapter 13. — Page 85. 

133. What is a quadruple expansion engine ? 

134. How do you determine the combined ratio 
of expansion for an engine of this type ? 

135. How do you determine the actual expansion 
rate in practice ? 

136. What is a jet condenser? 



QUESTIONS. 165 

137. What is an air pump? 

138. What is a hot well ? 

139. What is a surface condenser? 

140. What is a circulating pump ? 

141. What are the advantages and disadvantages 
of the two systems of condensing the exhaust steam 
from an engine ? 

142. How much water is required to operate a 
condenser, compared with the amount used to gen- 
erate the steam ? 

143. What plans are adopted for the purpose of 
saving water ? 

144. What other kinds of condensers are some- 
times used, and what are their advantages ? 

145. What objections are sometimes made to con- 
densing engines ? 

Chapter 14.— Page 90. 

146. How much does a cubic foot of water weigh ? 

147. How many gallons are therein a cubic foot ? 

148. How much does a gallon of water weigh ? 

149. How many cubic inches are there in a U. S. 
standard gallon ? 

150. What is a foot pound ? 

151. How is the duty of a pumping engine rated ? 

152. Is there more than one method for this pur- 
pose ? 



1 66 QUESTIONS. 

153. If the height of a column of water is given, 
how would you calculate its pressure per square 
inch ? 

154. If the pressure is given, how would you 
determine the height? 

155. How would you determine the total resist- 
ance per square inch that a water piston must over- 
come ? 

156. If the source of supply is above, or below 
the pump, will it affect the result ? 

157. How would you determine the number of 
foot pounds developed by a pumping engine ? 

158. How would you determine the time re- 
quired to burn 100 pounds of coal ? 

159. How would you determine the travel of the 
water piston while burning 100 pounds of coal ? 

Chapter 15. Page 96. 

160. How would you determine the time required 
for 1000 pounds of steam to pass through the cyl- 
inders ? 

161. What allowance should be made for the 
water that passes off with the steam ? 

162. What would you consider a satisfactory re- 
sult of a pumping engine test ? 

163. What is the objection to a fly wheel on a 
pumping engine ? 



QUESTIONS. 167 

164. What device has been adopted whereby a 
fly wheel is dispensed with ? 

165. Can you explain the design and operation 
of the "high duty attachment ?" 

166. What is the chief object in adopting it ? 

167. How is it cushioned ? 

168. How does it operate in case the water main 
bursts ? 

Chapter 16. — Page ioi. 

169. How do you calculate the pressure that a 
pump will work against ? 

170. How do you calculate the steam pressure 
necessary to operate a boiler feed pump ? 

171. How do you determine the diameter of 
water piston for a pump ? 

172. How do you determine the diameter of 
steam piston for a pump ? 

173. What is the limit of speed for a pump ? 

174. How do you calculate the capacity of pumps 
at 100 feet piston speed per minute ? 

175. How do you determine the diameter of 
pump piston to move a given quantity of water per 
minute ? 

176. How do you determine the speed of water 
in a pipe ? 

177. How do you determine the diameter of pipe 
to deliver a certain quantity of water per minute ? 



l68 QUESTIONS. 

Chapter 17. — Page iio. 

178. What causes an injector to become unreli- 
able and finally worthless ? 

179. Why does an injector refuse to start when 
hot water is supplied to it ? 

180. Does the height of the lift affect the capacity 
of an injector ? 

181. Is it practical to design an injector that will 
deliver water against a much higher pressure than 
the steam pressure used to operate it ? 

182. Explain the theory of the injector ? 

183. How do you calculate the velocity of steam 
under given conditions ? 



Chapter 18. — Page 119. 

184. What is the object in covering a steam pipe 
with a non-conductor of heat ? 

185. How do you determine the amount of steam 
condensed per hour in an uncovered pipe ? 

186. How do you compute the amount of coal 
wasted in this way ? 

187. How do you calculate the number of heat 
units lost ? 

188. How is the horse power lost by condensation 
in pipes determined ? 



questions. 169 

Chapter 19. — Page 125. 

189. What appliance should be provided for 
reducing the boiler pressure to a low pressure for 
heating purposes ? 

190. What is the effect of adding 5 pounds back 
pressure to an engine ? 

191. Is there any loss when an engine exhausts 
into a heating system ? 

192. How would you calculate the power actually 
absorbed in doing work when exhausting into a 
heating system, or into the atmosphere ? 

Chapter 20. — Page 133. 

193. Is the temperature of steam raised by pass- 
ing it through a reducing valve ? 

194. What is specific heat ? 

195. What becomes of the latent heat of the 
steam, after it passes to the rooms to be heated ? 

196. How is the water of condensation returned 
to the boilers by means of a trap ? 

197. When a closed receiver and a duplex pump 
are used, how does the appliance operate ? 

198. When a trap is used what should be done 
with the cold water that returns when steam is first 
admitted to a heating system ? 

199. If a duplex pump is used to return the water 
of condensation, will it pump this cold water ? 

200. What is the object in heating it before it is 
pumped into the boilers ? 



SHUTTING DOWN A STEAM PLANT. 

As the time approaches for the machinery to be 
stopped, the engineer of the plant should see that 
the water level in the boilers is raised as high as it 
is safe to carry it while the engine is running, and 
after it is shut down the injector should be run 
until the gage glass is nearly full, in order to pro- 
vide for the loss of water while the boilers are shut 
down. If the plant is not provided with an in- 
jector the pump must be used, and steam turned 
into the heater, so that no cold water will reach 
the boilers. 

The fires should be banked, so that steam will 
not be generated until it is wanted, all of the damp- 
ers and doors closed, and the water columns shut 
off, so that if a gage glass breaks during the absence 
of the fireman, no further damage will result. 

During the last five minutes that the engine is 
run, more oil should be fed thrcugh the lubricator, 
or through a special hand pump, than is required 
at other times, so that all of the internal parts will 
be protected from rust while at rest. Before the 
throttle valve of a condensing engine is closed care 
should be taken to know that the injection water 
is shut off so that it cannot be drawn into the cyl- 
inder. After the engine is shut down it should be 
nicely cleaned with waste, and all of the sight feed 
oil-cups filled ready for use. An inspection of the 
steam and water valves, to see that they are open 
or closed, as the case requires, completes the work. 

170 



LIST OF ILLUSTRATIONS 



PAGE. 

1. The Workshop of the Author, 4 

2. High-Speed Engine with Corliss Valve Gear 6 

3. Engines Running " Over" and u Under,". . 14 

4. Tubular Boiler 19 

5. Vertical Boiler With Brick Setting 25 

6. Pop Safety Valve 30 

7. Vertical Boiler Without Brick Setting .... 36 

8. Water Tube Boiler 47 

9. An Efficient Safety Boiler 53 

10. A Condensing Engine 58 

11. A Defective Indicator Diagram 63 

12. The Lippincott Planimeter 68 

13. The Willis Planimeter 69 

14. Cross Compound Engine 74 

15. Tandem Compound Engine 79 

16. Triple Expansion Engine 84 

17. Surface Condenser and Cooling Tower 89 

18. Vertical Cross Compound Pumping Engine, 95 

19. Duplex Pumping Engine . 100 

20. An Altitude Gage 109 

21. Duplex: Hancock Inspirator 118 

22. The Brainerd Steam Trap 124 

23. Direct Connected Fan . 132 

24. Pump and Receiver 138 

25. Quadruple Sight Feed Lubricator 139 

26. Left Hand Engine 140 

27. Right Hand Engine 141 

28. Vertical Cross Compound Engine 142 

1 



INDEX OF CHAPTERS 



Chapter i Page 15 



2 

3 

4 

5 
6 

7 
8 

9 
10 

11 

12 

x 3 
14 

15 
16 

17 
18 



19 

20 

Appendix 

Examination Questions 



20 
26 

3i 
38 
48 

54 

59 
64 

70 

75 
80 

85 
90 

96 

101 

no 

119 
125 

1 33 
!55 



2 



INDEX OF SUBJECTS 



In the following index the page on which the 
chapter begins, containing the subject referred to, 
is given because the author wishes to have enough 
of the matter read and studied to give a clear idea 
of the information contained. Reading a single 
page does not always accomplish this, and as it re- 
quires but a short time to read each chapter the in- 
dex is arranged so as to encourage a complete study 
of the whole book, and at the same time it locates 
each subject in its proper place. 



A 

CHAPTER 

Accumulator for high duty attachment, 15 

Air pump, . . , 13 

Amount of steam condensed in uncovered pipes, 18 

radiators, 20 

Area of rivet, to calculate, 2 

safety valves, . . 3 

A. S. M. E. rating for powei of boilers, ........ 6 

Attachment, high duty, 15 

Automatic injector, 17 

B 

Boileis, safe working pressure of, 2 

strength of joint in, 2 

horse power of , . . . 6 

heating surface of, « .... 4 

3 



INDEX. 

CHAPTER 

Boiler, water leg of, 2 

tests, how to conduct, 4 

duty of a, 5 

circulation of water in a, 1 

feed pump, 16 

Bolts, stay, why made hollow, 2 

Braces, distance between, 2 

British Thermal Unit, 1 

By-pass valve, 11 

C 

Calculating area of rivet, 2 

moisture in steam, 5 

Capacity of injectors, 17 

pumps, 16 

Calorimeter, 5 

Centennial rating for power of boilers, 6 

Circulation of water in a boiler, 1 

Cleaning injectors, 17 

Column of water, pressure of a, 14 

Condenser, injector, 13 

Conducting boiler tests, 4 

Constant, Horse Power, 9 

Compound engine, horse power of a, 10 

horse power constant of a, . . 9 
object sought in building, ... 9 

receiver for a, 11 

size of cylinder for a, n 

tandem, 11 

4 



INDEX. 

CHAPTER 

Compound engine, cross, n 

steeple, n 

Combined ratio of expansion for a compound 

engine, 10 

Combined ratio of expansion for a triple expan- 
sion engine, .12 

Combined ratio of expansion for a quadruple ex- 
pansion engine, 13 

Condenser, jet, 13 

surface, 13 

siphon, 13 

Cooling towers, 13 

Cylinder, warming a, 7 

D 

Defective diagram, 8 

Density, maximum of water, 20 

Diameter of pipe for a given quantity of water, . . 16 

water piston, 16 

steam piston, .16 

Distance of weight from fulcrum on safety valve 

lever, 3 

Distance between braces, 2 

Double acting engine, rule to calculate power of a, 7 
Double engine, rule to calculate the power of a, 9 

Duty of an engineer, 7 

Duty of a boiler, 5 

Duty of a pumping engine, 14 

5 



INDEX. 

CHAPTER 

E 

Engineer, practical, i 

theoretical, i 

first duty of an, 7 

Engine, starting an, 7 

single acting, to calculate horse power 

of a, 7 

single acting with two cylinders, to cal- 
culate the horse power of a, 7 

double acting, to calculate the horse 

power of a, 7 

double, to calculate the horse power of a, 9 
compound, to calculate horse power of a, 9 
compound, object sought in building, . . 9 

simple, horse power constant of a, 9 

compound, horse power constant of a, . . 9 
compound, combined ratio of expansion 

for a, 10 

compound, receiver for a, 11 

compound, size of cylinders for a, n 

tandem compound, 11 

cross compound, 11 

steeple compound, 11 

triple expansion, horse power of a, .... 12 
triple expansion, combined ratio of ex- 
pansion for a, 12 

quadruple expansion, 13 

6 



INDEX. 

CHAPTER 

Engine, quadruple expansion, combined ratio of 

expansion for a , 13 

pumping, duty of a, 14 

pumping, foot pounds developed by a • • 14 

steam, indicator, 8 

Equivalent evaporation, 5 

weight of wood, 4 

Excessive pressure, penalty for carrying, 6 

Expansion, ratio of, 10 

Exhaust steam, heating by, 19 

F 

First duty of an engineer, 7 

Fixed injector, 17 

Foot pound, 14 

valve, • 17 

Fusible plug, . . 2 

Fulcrum of safety valve, 3 

G 

Gaseous steam, 1 

Gear, valve, 7 

Greatest density of water, 14 

H 

Heat, specific, . . . . , ... 20 

sensible, of steam, , . . 4 

latent, of steam, 4 

total, of steam, 4 

unit, 1 

units used in developing power, 19 

7 



INDEX. 

CHAPTER 

Heat units lost by condensation, , 18 

Heating by exhaust steam, 19 

surface of boilers, 4 

High duty attachment, ....... 15 

accumulator for, 15 

Hot well, 13 

Hollow stay bolts, 2 

Horse power of boilers, 1 6 

standards for calculating the, 6 

of a single acting engine, ,7 

of a single acting engine with two 

cylinders, 7 

of a double acting engine, 7 

of a double engine, 9 

of a compound engine, 9 

of a triple expansion engine, 12 

constant of a simple engine, 9 

of a compound engine, . 9 

Hydraulic pump, .' 16 

I 

Indicator, the steam engine, 8 

diagram, a defective, 8 

Injector condenser, 13 

Injector, lifting, 17 

nonlifting, 17 

automatic, 17 

fixed, 17 

theory of the, 17 

8 



INDEX. 

CHAPTER 

Injector, to clean an, 17 

J 

Jet condenser, 13 

Joint, strength of a, in a steam boiler, . 2 

L 

Latent heat of steam, 4 

Lever, distance of weight on, from fnlcrnm on 

safety valve, 3 

weight on safety valve, , . . 3 

length of a, for safety valve, 3 

Lifting injector, 17 

Loss by condensation, 18 

by using reducing valve, 20 

Loop, steam, 18 

M 

Maximum density of water, ... 1 

Measurement, unit of, for heat, 1 

Mean effective pressure, 8 

Molecules of water, 1 

Moisture in steam, 5 

N 

Nonlifting injector, 17 

P 

Penalty for carrying excessive pressure, . . : 6 

Piston, steam, for pump, 16 

water, for pump, 16 

pump, 16 

Pipes, uncovered, steam condensed in, 18 

9 



INDEX. 

CHAPTER 

Pipe covering, thickness of, ... 18 

Pipes, velocity of water in, 16 

diameter of, for given velocity of water, . . 16 

Plug, fusible, 2 

Plunger pump, 16 

Pounds pressure, i 

foot, 14 

Power pump, 16 

Practical engineer, % 1 

Pressure, safe working, of steam boilers, 2 

to lift safety valve, 3 

mean effective, 7 

of a column of water, 14 

that a pump will work against, 16 

Pump, air, 13 

hydraulic, 16 

boiler feed, 16 

tank, 16 

pressure necessary to drive a, 16 

diameter of steam piston for a, 16 

diameter of water piston for a, 16 

pressure that a, will work against, ... .16 

and receiver, 20 

Pumps, speed of, 16 

capacity of, 16 

Pumping engine, foot pounds developed by a, . 14 

duty of a, 14 

10 



INDEX. 

CHAPTER 

Q 

Quadruple expansion engine, 13 

combined ratio of 

expansion for a, 13 

R 

Ratio of expansion, 10 

combined, for a compound en- 
gine, 10 

combined, for a triple expan- 
sion engine, 12 

combined, for a quadruple ex- 
pansion engine, 13 

Radiators, steam condensed in, 20 

Receiver and pump, 20 

for a compound engine, n 

Return traps, 20 

Reducing valves, 20 

loss by using, . . . . 20 

Rivet, area of a, ... 2 

S 

Safe working pressure of steam boilers, 2 

Safety valve lever, distance of weight from ful- 
crum on a, 3 

weight on a, 3 

pressure to lift a, 3 

length of a, 3 

Safety valve, rule to determine area of a, 3 

Sensible heat of steam, 4 

11 



INDEX. 

CHAPTER 

Separator, use of a, 19 

Simple engine, horse power constant of a, 9 

Single acting engine, to calculate the horse pow- 
er of a, ..... 7 

with two cylinders, the 
horse power of a, . . . 7 

Size of cylinders for a compound engine, 11 

Siphon condenser, 13 

Specific heat, i : 20 

Speed of pumps, 16 

Stay bolts, why are, made hollow, 2 

Standards for calculating horse power of boilers, 6 

Starting the engine, 7 

Steam, what is, 1 

saturated, 1 

wet, 1 

superheated, , 1 

gaseous, ,\ 1 

velocity of, 17 

moisture in, 5 

Steam engine indicator, 8 

Steam piston for pump, 16 

Steam condensed in uncovered pipes, 18 

in radiators, 20 

Steam loop, 18 

Steeple compound engine, 11 

Strength of joint in a steam boiler, 2 

Surface condenser, 13 

12 



INDEX. 

CHAPTER 

T 

Tandem compound engine, . ...... n 

Tank pumps, ..'../. : , .... 16 

Test of boiler, how to conduct a, . . . , 4 

Theoretical engineer, . , .;.... 1 

Thermal Unit, British, . . . ........ 1 

Theory of the injector, /. 17 

Thickness of pipe covering, . . . 18 

Total heat of steam, .,.;.. 4 

Towers, cooling, . . , 13 

Traps, return, 20 

Triple expansion engine, the horse power of a, 12 

combined ratio of ex- 
pansion for a, .... 12 
U 

Unit of measurement for heat, 1 

of heat, , . ... 1 

British Thermal, 1 

Units, heat, lost by condensation, 18 

used in developing power, -.19 

Uncovered pipes, steam condensed in, 18 

Use of separators, ,19 

V 

Valve, safety, to determine the area of a, 3 

to determine pressure that will lift a , 3 
to determine length of lever for a, 3 
to determine distance from fulcrum 
to weight, 3 

i3 



INDEX. 

CHAPTER 

Valve, safety, to determine weight for a, 3 

by pass, ...,..' . . u 

reducing, 20 

foot, , 17 

gear, 7 

Velocity of steam, 17 

water, 16 

W 

Water, weight of, 14 

pressure of a column of, . 14 

piston for a pump, . 16 

pressure that a pump will work against, 16 

circulation in a boiler, 1 

molecules of, . . 1 

maximum density of, 20 

leg of a boiler, ,,,...... 2 

velocity of, r . . 16 

Warming the cylinder, 7 

Weight, distance of, from fulcrum on safety valve 

lever, 3 

on safety valve lever, 3 

of water, .14 

Well, hot, , 13 

What is steam ? 1 

What is the fulcrum on a safety valve ? 3 

What is a calorimeter ? , . 5 

Working pressure for steam boilers, 2 

Wood, equivalent to weight of coal, 4 



ADVERTISEMENTS. 



q^HE FOLLOWING PAGES contain the adver- 
tisements of reliable parties who deal in the 
specified goods. They are cordially recommended 
to steam users, engineers and others interested, as 
giving satisfaction to all who deal with them. 

When you send orders for their goods, or re- 
quests for their catalogues, you are earnestly re- 
quested to state that you saw their advertisements 
in this book. 

By doing so, you will confer favors on adver- 
tisers and the publisher. 



Repairing Valves. 



What we now call common brass valves, in order to dis- 
tinguish them from those with disks that are easily 
removed, were almost universally used to control the flow 
of steam in both large and small pipes, when the writer 
secured his first situation as an engineer. 

When new they were not always tight enough to entirely 
shut off the steam when closed, and those that were in 
good order when first put into service seldom remained 
so. The natural consequence was that they were allowed 
to leak until the waste of steam was excessive. Then 
emery, ground glass, or some other abrasive substance was 
applied to both disk and seat, and the process of grinding 
in commenced. It proved to be both tedious and expen- 
sive, but was the best way known at that time. 

When a better globe valve was invented, the body con- 
sisting of steam metal and the disk made of hard rubber, 
all this was changed. A new valve of this kind is put 
into service, steam is admitted until it is thoroughly 
heated, the wheel turned and the disk pressed firmly to its 
seat. This makes a perfectly tight joint that remains so 
until the disk is worn out, when the bonnet is removed, a 
new disk put in, the bonnet replaced and the valve made 
as good as new. 

The disk holder is grasped by a pair of gas tongs, and 
the nut which holds the disk in place unscrewed with a 
wrench, bringing the disk with it, thus making the re- 
moval of a worn-out disk a very simple matter. 

New disks of proper sizes should always be kept on hand 
ready for immediate use, as leaky valves cause the loss of 
many dollars worth of steam every year, therefore a valve 
that can be easily repaired is the best to purchase, as it will 
soon save enough to pay its cost. 

2 



JENKINS BROTHERS' YALYES 




*+ 



f < $ 



Globe, Angle, Check, 
Cross, Y, Safety, &c, 
both screwed and flanged, 
are extra heavy and are 
made of the best steam 
metal. 



Have the genuine Jenkins Disc, Disc Removing Lock 
Nut and Patent Keyed Stuffing Box. If you want the 
genuine ask your dealer for Valves manufactured by 
Jenkins Brothers, which are always stamped with Trade 
Mark like cut. 



JENKINS BROS., New York, Boston, Philadelphia, Chicago. 



PACKING FLANGED JOINTS. 

»•« 

One of the unpleasant jobs that an engineer has to do is to 
pack the flanged joints in his plant. These joints are fre- 
quently located in inconvenient places, and as the old pack- 
ing fails when the machinery is required for use, it must be 
renewed while the parts are as hot as steam can make them. 

One kind of packing that the writer has used many 
times, became soft as soon as steam was admitted to the 
newly packed joint, making it necessary to screw up the 
nuts until the two flanges were nearly in contact with each 
other. This caused all of the hollow spots and the space 
around each bolt to be nicely tilled with the packing, re- 
sulting in a perfectly tight joint in which the smallest pos- 
sible amount of packing was exposed to pressure, thus in- 
suring its durability. However, the necessity of following 
up a joint after steam was admitted to it was an objection 
in the estimation of some engineers, therefore the manu- 
facturers of this kind of packing improved their product 
until they produced an article that needs no attention after 
once fitted into place, with the nuts on the bolts properly 
adjusted. 

The actual cost of the sheet packing required for a joint 
is small when compared with the cost of labor required to 
get the packing into place, and the inconvenience of shut- 
ting off the steam while doing the work, but still there is 
no economy in buying heavy packing, when thickness and 
surface are considered, if a lighter kind will answer every 
purpose. 

The ordinary rubber packing with cloth insertion, made 
by nobody in particular, or at least we never find the mak- 
er's name stamped on it, is fast becoming obsolete and justly 
so too, for it is usually made of inferior materials and is 
not worthy of comparison with an improved kind that 
always has its maker's name upon it as a guarantee. 

4 




Makes perfect joint immediately ; does not have to 
be followed up. 

Makes joint that will last for years on all pressures of 
steam. 

Does not rot, burn, blow or squeeze out. 

Weighs 30 per cent, less than many other packings, 
therefore the cheapest and best. 



JENKINS BROS., New York, Philadelphia, Boston, Chicago. 



GRAPHITE LUBRICATION 



-*♦*- 



The first experience of the writer with graphite was under the fol- 
lowing circumstances: The oil cup on the main bearing of his engine 
failed to feed properly, and it was not discovered until the iron was 
almost hot enough to melt the Babbitt metal. The cap was taken off, 
the shaft wiped clean, and beef tallow T or suet, just as it came from 
the store was coated thickly with graphite and laid on the shaft. The 
cap was replaced and the engine started up at once. At the usual 
time for shutting down, that bearing was at its normal temperature, 
and there was no more trouble with it. 

In another case a large bronze bearing located in the upper part of 
a mill was not sufficiently lubricated, and it was not accessible while 
the machinery was in motion, it took fire and made it necessary to 
shut down. It was cooled off with water, and the shafting started up 
with no other precaution than to provide plenty of ordinary tallow 
and graphite for lubrication. During the first hour it was quite warm, 

but gradually cooled down until it was perfectly safe, and it gave no 
more trouble. It w^ould have cost many dollars to have taken down 
this bearing and repaired it. 

These two extreme cases are sufficient to show the real value of this 
lubricant. 

When mixed with cylinder oil it makes an excellent lubricant for 

steam pipe threads, and when it is desired to take the pipes down, it is 

possible to do so without breaking the fittings. 

6 



A NEW TRICK. 

HAVE YOU TRIED IT? 




A bright engineer said, "Do I use Dixon's Flake 
Graphite ? You bet I do and I use it in a squirt can. 
I take a new, clean can and fill it with Dixon's Flake 
Graphite and I find it will squirt it easier than oil. It is 
the most convenient way to use Graphite. If the end of 
the spout is a trifle too small a bit of it can be filed off." 

[£!P Be sure you get Dixon's Pure Flake Graphite in 
the original can — the one with the red label. Then you 
will have the genuine. 

SEND FOR OUR PAMPHLET. 



JOSEPH DIXON CRUCIBLE CO. 

JERSEY CITY, N. J. 

7 



The Inspection and Insurance 
of Steam Boilers. 



When a steam boiler explodes and causes the loss of much property, 
it affords some satisfaction to know that it was insured and that the 
claim will be paid promptly. It is much better and cheaper, how- 
ever, to dispense with the explosion altogether, and for this reason the 
word "inspection" is placed before the word "insurance" in the 
above title, because careful and conscientious inspection will prevent 
many of the explosions that prove so disastrous. 

Trained inspectors while examining the internal and external parts 
of steam boilers find many defects that would not be discovered by 
anybody that has given less attention to this important work, and 
when these are pointed out, remedies can be applied before the faults 
become dangerous. 

During these inspections, the effects of improper management of 
steam boilers are frequently apparent to the inspector, who points 
them out so that the objectionable practices may be discontinued be- 
fore serious trouble results. 

This is the most important part of the whole system, but when 
some hidden defect in a boiler so weakens the structure that it fails 
and does much damage, the indemnity paid by the insurance company 
may make all of the difference between success and failure in busi- 
ness on the part of the unfortunate owners. 

The moral support afforded under such circumstance is also worthy 
of consideration, for if an exploded boiler was insured in a reliable 
company, who employ only the best inspectors, it shows that all 
reasonable precautions along this line had been taken. 

8 




THOROUGH INSPECTIONS 



AND 



Insurance against Loss or Damage to Property 
and Loss of Life and Injury to 

Persons Caused by 

Steam Boiler Explosions. 



► ♦ ■« 



J. M. ALLEN, President. 

WM. B. FRANKLIN, Vice-President 

F. B. ALLEN, Second Vice-President. 
J. B PIERCE, Secretary, 

L. B. BRAINERD, Treasurer. 

L. F. MIDDLEBROOK, Asst Secretary. 

9 



BENEFITS TO BE DERIVED 

FROM THE USE OF 

POP SAFETY VALVES. 



On account of the vibration and unsteady motion to 
which locomotive and marine boilers are subjected, it is 
necessary to use Pop Safety Valves on them, but there are 
benefits to be derived from their use on stationary boilers 
that are worthy of careful consideration. 

It is desirable, if not actually necessary, in a large ma- 
jority of cases, to carry the highest safe pressure on boilers 
now in use, therefore safety valves that will open and 
close promptly, with a slight variation of pressure, give 
the best satisfaction, because they remain tightly closed 
until the maximum pressure is reached, then they open at 
once, discharge enough steam to slightly reduce the pres- 
sure, after which they close promptly and thus prevent un- 
necessary waste of steam, hence they are the most economi- 
cal kind to use. 

When a Pop Valve opens it discharges steam very rapid- 
ly, so that there is little danger of the pressure increasing 
after the safe limit is reached. This gives it a right to the 
name " safety valve," and this has undoubtedly prevented 
many boiler explosions. 

A valve of this kind may be locked up so that it cannot 
be overloaded, either accidentally or intentionally, which 
is a valuable feature, for when an engine is overloaded, 
there is a great temptation for the engineer to increase the 
pressure to meet the conditions, and in this way boilers 
are subjected to more stress than they can safely stand. 

10 



ASHTON POP VALVES. 




Guaranteed to Give Perfect 

Satisfaction. 

Made of Best Material. 

Insuring Greatest 

Efficiency and Durability. 

Indorsed .and recommended by leading- 
Engineers and Architects. Superior in 
quality. 

THE BEST AND CHEAPEST. 



MERITS AND REPUTATION UNEQUALED. 



Ashton 





■es. 



Have Non-Corrosive Move- 
ments and Seamless Drawn 
Tubes. Are Accurate, Dura- 
ble and Strictly High Grade. 




Send for Catalogue W. 



* i^i t- 



THE ASHTON YALYE CO., 



BOSTON. 



NEW YORK. 
11 



CHICAGO. 



The Use of Sheet Packing. 



When the writer was first employed as a steam engineer, 
it was not possible to get such good sheet packing as is 
found in common use at the present time, therefore it was 
necessary to spend much more time packing joints than 
w r e have to at the present time. There was one joint in 
the plant that he had charge of that was a source of much 
trouble, as it would frequently blow out, and it took two 
men half a day to pack it, because it could not be reached 
readily. 

All this is changed now for sheet packing that will last 
for years can easily be procured, and consequently is used 
extensively. 

The flanged joints on the plant in charge of the writer 
have been in use nearly seven years and show no signs of 
failure yet, which is a source of satisfaction to both 
owners and engineer. 

Where a rough joint is to be packed, thick packing 
should be used, but where the parts are smooth it is ad- 
visable to use thin packing, not only on account of saving 
the cost of too thick material, but because there is less 
liability of failure by blowing out, as there is less surface 
exposed to pressure. 

In these days of high pressures and long runs, it is 
especially advisable to use only sheet packing that is guar- 
anteed to withstand a high temperature, and that is known 
to be durable. 

12 



W/1/B0W PACKING 

The Best Flange Packing Made. 



32 

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a 

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CO 

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too 
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tzi £ £ 




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2%$ 


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Cf 


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use wi 
o hold 
OW 




CD 



THE COLOR OF RAINBOW PACKING IS RED. 

Notice our trademark of Three Rows of Diamonds extending throughout the entire 
length of each and every roll of Rainbow Packing. 

This Packing is especially adapted for very high pressure, and is 
not affected by any degree of steam heat. It will not harden under 
any degree of heat, or blow out, under the highest pressure, and will 
make an air, steam, hot or cold water joint equally well. 

Sole manufacturers of the well known Peerless Piston and Valve 
Rod Packing, Eclipse Sectional Rainbow Gasket, Hercules, Combina- 
tion, Honest John, Zero, Arctic, and Success Packings. 

Insist on having goods made by us, which are absolutely the highest 
grade in the market. 

MANUFACTURED EXCLUSIVELY BY 

PEERLESS RUBBER MFG. CO. 

16 WARREN STREET, NEW YORK. 

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17-23 Beal St. and 18-24 Main St., San Francisco, Cal. 

For Sale By All First-class Dealers. 

13 



The Value of 

FEED WATER HEATERS. 



In many of our large steam plants the value of feed water heaters 
is recognized and the best to be found are in constant use. This is 
very proper, but there are many small plants in which a heater is 
looked upon as a luxury rather than a necessity. It is quite possible 
to save 15 per cent, or more of the coal bill, by the use of this valu- 
able appliance, which is certainly sufficient to warrant its adoption in 
every case, but there is a much more important reason for its great 
popularity among those who understand the benefits to be derived 
from it. 

When a fire is built under a boiler the sheets expand according to 
the heat applied. If cold water is pumped into this boiler through a 
feed pipe that is connected into the bottom of the shell, the high 
temperature is reduced in one place, leaving the other parts as hot as 
they formerly were. The result of this is that while a part of the 
boiler remains expanded portions of it are contracted by the fall in 
temperature, and thus a great stress is brought to bear on portions of 
the shell and tubes. 

It is difficult if not impossible to determine the amount of stress so 
applied, but it is quite possible for it to exceed the stress that is 
caused by any ordinary working pressure of steam, and when we 
consider that this comes in addition to the steam pressure, it will be 
plain that to dispense with a Feed Water Heater is both expensive and 
dangerous. 



14 








The National Feed Water Heater 

Supplies Water to Boilers at 212°. 

mmmter It is Efficient, Reliable and 
8 Reasonable in Price. 




1,000,000 Horse Power Sold, 

Proves its Quality and 

Efficiency. 

Made in 30 Sizes, 5 to 6,000 
Horse Power. 



Material First Class and 
Guaranteed. 



-*♦+- 



THE KATIOWAL PIPE BEMLIN& CO.. 

145 LLOYD STREET, 

15 



OLD 

JOLLY 



That it's "just as good " as EUREKA 
don't work, if you have tried EU- 
REKA. It cures squeaky squirty 
engines. Prevents good engines from 
getting squirty and squeaky. 



Outlasts two 
or three times. 
Gives more pow- 
er. Costs one- 
half less in sea- 
son's run. 

Hine Eliminator. 

A Watch Dog, 

preventing 
water entering 
engiue cylinder 
and keeping 
oil out of boil- 
er. An insur- 
ance at moder- 
ate cost. Worth 
your consider- 
ation. 

The troublesome 
problem — how to lubri- 
cate the eccentric 
crank pin, etc., — in an 
economical, positive 
and cleanly manner at 
one-third the cost— is 
solved in this device. 






There are 
many imitations, 
but none with 
red diamond la- 
bel. Specify 
" Genuine." 



ROBERTSON 
Feed Water Heater. 

The Loop on 



top of copper 
coil returns the 
water down 
through and 
out where 
steam is the %i 
hottest. No 
higher in price 
than any other. 

Sent out on trial with 
sufficient grease for 
trial period, should 
warrant every one in 
trying one. An at- 
tractive booklet is 
yours for the asking. 




► • * 



JAMES L. ROBERTSON SONS, 204 Fulton Street, 



hsiie'W" yoirjk: 



16 




A 
WATCH 



an INDICATOR should be good 
years hence as at first. Some INDI- 
CATORS like some watches are made 
by contract to sell, and are dear at any 
price. A few dollars more will purchase 
an IMPROVED ROBERTSON 
THOMPSON. 
No indicator made has the same care in all details, particularly 
testing the springs. U. 8. Navy method and standard of 2% 
variation is followed. Sold at a price within reach of every engineer. 



in 



IMPROVED 

WILLIS 

PLANIMETER 

in velvet-lined, 
leather case. 




A marvel for 
accuracy, con- 
struction and 
durability. 



M. E. P. Read Direct from Scales. 
Price $18.00. 



THREE WAY VALVES. STRAIGHT WAY VALVES. 

ELBOW COCKS. NICKLED PIPING. 

TESTING OUTFITS, ETC. 



IMPROVED VICTOR 

REDUCING WHEEL 

always readj r for any speed or any 
stroke up so 6 ft. Fits any* indi- 
cator. Can be adjusted in five 
minutes ready for work. 
Price $15.00. 

►"♦-*- 




JAMES L. ROBERTSON SONS, 204 Fulton Street 



USTZE-W ^OZRZKI. 



17 



Show This 

To Your Friends . 

Purchasers of Wakernan's " ENGINEERING PRACTICE 
AND THEORY FOR STEAM ENGINEERS" ought 

also to be subscribers to SCIENCE AND INDUSTRY, a 

monthly magazine devoted to practical articles on the theory 
and practice of steam engineering and electricity. The articles are 
interesting, instructive and ABSOLUTELY ACCURATE. Each 
issue contains several engineering articles, and also includes an 
" Answers to Inquiries" department in which you can have perplex- 
ing questions about steam engineering fully and accurately answered 
and often illustrated. Send for a free sample copy of SCIENCE 
AND INDUSTRY. The subscription price is $1.00 a year. 

SPLENDID COMBINATION OFFER. 

A years subscription to SCIENCE AND INDUSTRY and a 
copy of Wakeman's " ENGINEERING PRACTICE AND THEORY," 
for $1.70. 

CANVASSERS WANTED. 
Any purchaser of this book who will visit, on our behalf, steam 
engineers aud firemen, mechanical and electrical engineers, elec- 
tricians, dynamo tenders, and others interested in steam engineering 
can retain twenty-five cents, as his commission, on all orders for this 
combination offer, sending us $1.45. A first-class chance to make 
money. 

SCIENCE AND INDUSTRY, 

SCRANTON, F>A. 
18 



Our Students Succeed. 



>-^- 



THOUSANDS of students of The 
International Correspondence 
Schools, Seranton, Pa , are receiv- 
ing higher wages for fewer hours' 
work than when they enrolled. The 
courses in Steam Engineering are 
intended especially for Engineers 
and Firemen who desire to qualify 
for advanced positions. 

Circulars and local ♦ <■ 
References free. 



<r <£♦ 



TZHZIE 



International Correspondence Schools, 



SCRANTON, F»A, 



19 



ONE CANNOT 

keep pace with the advantages of his 
profession unless he reads — reads — 
reads. Some of the technical press, pub- 
lish articles that are so full of math- 
ematical demonstrations, that very 
few receive any knowledge what- 
ever. The "Engineers' List" pub- 
lishes only such matter as will in- 
terest the actual operating Engineer. 
84 pages, well illustrated. Issued 
monthly for One Dollar a year. 

Sample copies sent on application 

We also have a complete line of 
Engineering books. 

If you want a paper that will 
thoroughly interest you subscribe for 
the "Engineers' List." 

Address all communications to 

ENGINEERS' LIST, 

471 FOURTH AYE., 

NEW YORK CITY. 

20 




IT HAS always been our policy to LET OUR 
LIGHT SHINE so that ENGINEERS, 
STEAM and ELECTRIC USERS of the 
WORLD might know that we make a SPMC- 
IALTY OF CATERING to their wants. 

We carry a FULL LINE OF ELECTRIC- 
AL SUPPLIES. 

We CONSTRUCT HEATING AND POW- 
ER PLANTS, and ALWAYS CARRY 
goods of the latest and best manufacture for STEAM, 
GAS, WATER and ELECTRIC PLANTS. 

Send for Catalogue. 



GEORGE I. ROBERTS & BROS. 



IN CORPORATED, 

471 & 473 Fourth Ave., Netv York City. 

21 



Engineers in 
Wood-working 
Establishments and 
Saw Mills 



Will find in the M ENGINE ROOM " Department 

OF 

the Wood-Worker 

Much that will interest them. MR. W. H. WAKEMAN, author of 
this volume, is a regular contributor to this department. 

THK WOODAYORKER is published monthly, at 
$1.00 a year. Samples are free on application to 



S. H. SMITH, Publisher, 



INDIANAPOLIS, IND. 
22 




Rockland, Me. 
Cling-Surface Mfg. Co., Boston Branch. 

Gentlemen : — Enclosed find photo, of two of my 16 in. belts which have been 
treated with Cling-Surf ace for some time but are in such fine shape that they have 
needed no application for the past two months. 

They run 3D in. slack and ail the time as here shown. The load sometimes jumps 
from zero to full load but there is no slip. If their work were different I could run 
them much slacker L. C. JACKSON, Ch. Engr., 

Rockland, Thomaston & Camden St. Ry. 

THESE BELTS ARE FULL OF CLING=SURFACE. 

They are merely examples of what Cling-Surface can do, as is the letter (to us) of 
Mr. W. H Wakeman, the very well informed author of this book : " An old belt so 
thoroughly soaked with oil that it was useless, after being washed with benzine, was 
treated with the Cling-Surface and in a short time it was doing good work. 

More than two months ago I put on a new belt and it has been treated with 
Cling-Surface exclusively. As it has not been taken up it is quite slack on account 
of its stretching as was expected, but the Cling-Surface prevents it from slipping 
although the belt is short with the working side on top, which I consider to be un- 
favorable conditions." 

Cling-Surface permanently stops all belt slipping and yet preserves the belt. Be- 
cause they will not slip they can be run easy or slack with all the advantages which 
this gives. And power will be much increased. 

Order. Test it in vour belts. Pav us onlv if results are as we sav. 



CLING-SURFACE MFG. CO., 

140-14~> Virginia St., Buffalo, X F, 

Boston, New York, Philadelphia, Chicago, St. Louis and New Orleans. 



Modern Machinery. 

A Monthly Mechanical Magazine Devoted to the 
Latest Advancement in 

Machinery and Machine Tools, 
Shop Equipments, 
Power Transmission, 
Steam and Gas Engines, 
Electrical Inventions, 

Mining and Metallurgy. 

Practical Hints on Steam Engine Practice comprise a 
valuable feature of each issue. 

" IMPROVEMENTS IN STEAM ENGINES," 

Is the subject of a Series of Articles by W. H. Wakeman, 
which will extend through the year 1901. 



SXJBSOBIPTIOIT: 
$1.00 PER YEAR IN ADVANCE 




218 La Salle Street, Chicago. 

24 



PUTNAM AUTOMATIC CUT-OFF STEAM ENGINE 



FITTED WITH THE 



NEW PUTNAM FLY-BALL GOVERNOR, 

With Link Attachment. 



PERFECTION of 




Steam Engine Catalogue and Full Information on Application. 

PUTNAM MACHINE CO., FITCHBURG, MASS., U. S. A. 

Long Distance Telephone 353-2. 
25 



THE ENGINEER 



Published Twice a Month, Cleveland, 



i.oo a Year. 



i immt » 



Devoted to Power Plant Engineering, 
Mechanical and Electrical. 



A Journal of Practice for Chief Engineers 
and Superintendents. 



■ <^> » 



Sample copies sent from 

The Engineer Publishing Co., 

BLACKSTONE BUILDING, - - CLEVELAND. 



26 



A 

Few 

Of 



POWELL'S 



STEAM 

SPECIALTIES, 




POWELL'S 

Class " A " 

SIGHT FEED 

Lubricator, 

for steam engines of all grades. In use on 
engines throughout the world. Try one when 
next in need. The Filler costs extra, but 
what a labor and profanity saver. 



Re=grinding Star Valves best for controlling 
steam and other fluids. Used wherever the 
initial cost is not the only consideration. 
Wearing qualities and re-grinding principle 
insure a long service, thus saving money. 



SIGNAL OILER. 

Lever Up, oil dropping. 
Lever Down, oil shut off. 
Operation of lever doesn't 
interfere with adjustment. 
A great oil saver. 

Signm. 44 Oiler 




OUR POCKET CATALOGUE 
Should be in the pocket of all engineers. A 
most complete reference. Its yours for the 
asking. Send for copy to-day. 




The WM. POWELL CO., 



CINCINNATI, OHIO. 



27 



VACUUM OILS. 



A EE MADE to fit every condition. They lubricated 
^ *• the Electric Light Plant in Pekin, and lubricated 
boats that brought the Allies. Besieger and besieged used 
them in South Africa. Ninety per cent, of the machinery 
at Paris turned on Vacuum Oils. In peace or war, all the 
same, they lubricate most on every kind of machinery ; 
not the same oil for all machines, but the right oil for 
each class. They do their work better and cheaper than 
all others ; that is why they are used in every corner of 
the world where machinery runs. 



VACUUM OILS are made only at our own works 
at Rochester and Olean, N. Y. Abroad they are distrib- 
uted from one hundred and thirty-three warehouses, and 
at home are sold in every city. 



VACUUM OIL COMPANY 

ROCHESTER, W. Y. 

28 



The Oil Filter 
of To-day. 



An Oil Filter that, meets every requirement 
of the practical up-to-date plant. 

CROSS OIL FILTERS 

Are the best, most durable, most practical, 
most economical Oil Filter on the market. 

Send for catalogue. 

THE BURT MFC. CO., 

Akron, Ohio, U. S. A. 

Largest Mfrs. of Oil Filters in the World. 



Not Theoretical 
But Practical. 



Not built to compete with others 

THE BURT EXHAUST HEAD 

Is in a class by itself. Condenses 
more steam, saves more time, trouble 
and mone} r than any other. 

Send for catalogue. 

THE BURT MFG. CO., 

Akron, Ohio, U. S. A. 

Largest Mfrs. of Oil Filters in the World. 






l l Cline M>y 



29 



Modern Examinations 

OF" 

STEAM ENGINEERS, 

Or Practical Theory Explained and Illustrated. 

mm 

By W. H. WAKEMAN. 

Size 6x8 Inches. 272 Pages. Handsomely Bound in Cloth. 

This book was written for engineers, firemen and others who are 
preparing to take an examination for a license wherever one is re- 
quired, and to enable them to do better work wherever a steam engine 
is found. It gives in a plain, practical way the information required 
for this purpose. 

It is divided into fifty-three chapters, which treat of the various 
parts of the steam plant, from a practical standpoint. Beginning with 
the steam engine, there are twelve chapters treating of the valves and 
other parts This part of the boo*: contains numerous numerical 
examples of the calculations for the various parts, which puts the sub- 
ject before the reader in a manner that is easily understood. 

Under the subject of boilers, the matter will be found of special 
interest, as numerous examples are fully worked out and explained. 
After covering the subjects of piping, exhaust steam heating, strength 
of materials and other allied subjects, 300 examination questions are 
given, with an index which shows where the answers can be found. 

ENGINEERING PRACTICE AND THEORY 

is not a duplicate of the above described work, therefore both books 
should be in the possession of everybody interested in steam engineer- 
ing, as they contain 500 examination questions, which are fully 
answered. Modern Examinations of Steam Engineers, will be 
sent to any address on receipt of $2.00. 
Direct orders to the author, 

W. H. WAKEMAN, 
04 Henry Street, NEW HAVEN, CONN. 



Stop Wasting Fuel!! 



And utilize the waste heat going up your chimney 
SAVING 10 TO 20 PER CENT. 

This should be worth consideration by any engineer, and 
the only practical way to do it is by using 

GREEN'S fuel 
ECONOMIZER, 

Which is to the boiler what the fly wheel is to the engine 
or the storage battery to the generator — uniformity of 
operation being a great factor of economy — purer feed 
water — saving of boiler repairs — more steam and less 
coal and ashes to handle — general satisfaction all 
around in the boiler room — can be applied to any type of 
boiler without stoppage of works — used successfully with 
natural, forced and induced draft — over 30,000,000 H. P. 
in use. 

THE GREEN FUEL ECONOMIZER CO. 

MATTEAWAN, IN. Y. 
Write for Booklet. 



31 



PRACTICAL 

Guide for Firemen, 

CONTAINING 

Instructions and Suggestions for the Care and Management 
of Steam Boilers, Pumps, Injectors, Etc. 

By W. H. WAKEMAN. 

65 Pages, 4 x 6^ inches. 14 Illustrations. Bound in Cloth. 

This book is an elementary treatise, and is intended to give the 
duties of a fireman, or one in charge of a small steam plant, in as sirn- 
pie and concise a manner as possible, and to furnish information that 
will enable him to operate such a plant successfully and economically. 



CONTENTS. 

I. Introduction. 

II. First duties in the morning. 

III. Carrying fires and removing ashes. 

IV. Steam pressure and water level. 
V. Boiler feeders. 

VI. Receivers and return traps. 

VII. Caring for water and steam gages. 

VIII. Leaving the boiler at night. 

IX. Incrustation and scale. 

X. Accidents. 

XL Preparing for inspection. 

XII. Boiler inspection. 

XIII. Suggestions. 

XIV. The prevention of smoke. 



Sent to any address on receipt of 50 cents. 

Direct orders to the author, 

W. H. WAKEMAN, 

€4 Henry Street, NEW HAVEN, CONN* 



INDICATORS 



1 



BACHELDER, EXCELSIOR, "I. H." THOMPSON. 

PLANIMETERS, 



REDUCING WHEELS, 

Ideal and Peerless, 



Polar, Lippincott. 




OIL FILTERS, 

SEPARATORS, 

OIL EXTRACTORS, 

GRATE BARS, 

DAMPER REGULATORS, 
'< SOOT-SUCKER" TUBE CLEANERS, TUBE BLOWERS. 



"BEE 



99 BRAND PACKING, GUM CORE, SQ. 
FLAX AND RING. 

Send for Catalogue. 



JOHN S. BUSHNELL CO., 

120 LIBERTY ST., N. T. 



33 



BOOKS 



IFOR ENGINEERS, FIREMEN ^NID 
STEAM USERS. 



THE STEAM ENGINE INDICATOR AND ITS APPLIANCES. 

Being a comprehensive treatise for the use of Constructing, Erecting and Oporat. 
ing Engineers, Superintendent-. Master Mechanics, Students, etc., describing in a 
clear and concise manner the Practical Application and Use of the Steam Engine In- 
dicator, with many Illustrations. Rules, Tables and Examples for obtaining th< 
results in the Economical Operation of all classes ot Steam. Gas and Ammonia En- 
gines, together with original and Correct information on the Adjustment of Valves 
and Valve Motion, Computing Horse Power of Diagrams, and extended instructions 
for Attaching the Indicator. Its Correct Use, Management and Care, derived from 
the author's practical and professional experience, extending over many years, in the 
Construction and Use of the Steam Engine Indicator, by Wm. Houghtaling. 300 
pages. Nearly 150 Engravings. 20 full page tables. Handsomely bound in silk 
cloth, Price $2.00. 

HANDBOOK OF CORLISS STEAM ENGINES. 

By F. W. Shillitto. Jr., describing in a comprehensive manner the erection of 
Steam Engines, the adjustment of Corliss Valve Gear and the care and management 
of Corliss Steam Engines ; with full page illustrations and complete descriptions of 
the leading Corliss Engines. Illustrated by 64 original engravings, 2-24 page?, hand- 
somely bound in green silk cloth, Price $1.00, 

THE DESTRUCTION OF STEAM BOILERS. 

Being a Practical treatise on the Destruction of Steam Boilers from the effects of 
Incrustation and Corrosion, with Simple Methods for Preventing the same, etc. By 
W. H. Wakeman. Pamphlet 6 in. by 9 in., illustrated. Price 25 cents. 

REFRIGERATION AND ICE MAZING AND REFRIGERATING 

MACHINERY. 

Being a Practical Treatise on the Construction, Operation and the Care and Man- 
agement of Refrigerating Machinery. By \V. H. Wakeman. Pamphlet 6x9 inches, 
fully illustrated. Numerous valuable tables, etc. Price 25 cents. 

STEAM BOILER CARE AND MANAGEMENT. 

By Frederick Keppv. M. E Beinsz useful, common sense information on the 
practical and safe operation of Steam Boilers on Land and Sea. Intended for th< 
of Engineers. Firemen and Steam users. Illustrated by 41 engravings, BO pi 
6x9 inches. Price 25 cents. 



The above or any of our books sent by mail, at the publication price, free of postage, 

to anv address in the world. 

THE AMERICAN INDUSTRIAL PUBLISHING CO., 

Publishers, Booksellers and Importers. 
BRIDGEPORT, CONN., - - - U. S. A. 

34 



The BRAINERD STEAM TRAP. 



Patented in United States and Foreign Countries. 
A simple and absolutely reliable Machine. 
Compare the capacity of the BRAINERD STEAM TRAP 
with many of other make. 




We guarantee to discharge condensation as fast as received into Trap. We guar- 
antee the Trap valves on our different size Traps to be equal to the areas of the inlet 
and outlet standard pipe sizes. We guarantee to elevate water from 10 to 200 feet 
above level of Trap. We guarantee our Copper Floats to withstand 300 pounds 
steam pressure per square inch. Our valve gear is made of special phosphor Bronze 
Metal. Our Traps fitted with by-pass strainer and mud drain, and we claim for 
this Trap to discharge from 90 to 500 per cent, more water than any other float-trap 
on the market— based on its discharge — the cheapest Trap built in this country. To 
responsible parties Traps sent out on 30 days trial. We renew the valve gear at 
cost when worn out. Here is the guaranteed capacity of these Traps under 110 
pounds steam presssure. One-half inch, 1,080 gallons per hour; three-quarter inch, 
2,680 gallons per hour; one inch 3,840 gallons per hour; one and one-half inch, 
7,790 gallons per hour. In use by the War Department shore service. U. S. Govern- 
ment war ship equipment, bleacheries, power houses, sugar refineries, breweries, 
and in foreign service. Write to us for circulars, references, prices and discounts. 
Your favors will receive our prompt attention. 

BRAINERD STEAM TRAP CO., 



12 HOWES ST., 



Boston, Mass. 



35 



Sellers' Restarting Injector. 




IS RECOMMENDED to users who desire a strictly 
first-class machine at moderate cost. It is per- 
fectly automatic, has wide range of capacities and 
raises water promptly with hot or cold pipes. Ex- 
tremely simple, has few parts and easily repaired. 
All parts interchangeable and made of best bronze 
which insures good wearing qualities. The workman- 
ship is perfect. The overflow valve is on combining 
and delivery tube which leaves overflow open so that 
a leaky valve in steam pipe will not over-heat water 
in feed pipe when Injector is shut off. Send us a 
postal, and let us mail you a Bpecial catalogue de- 
scribing this Injector. 



JENKINS BROS,, New York, Philadelphia, Chicago, Boston 



36 



Mar- 12 19OI 



\ 



